Build modified streamline images

The official image from streamline does not currently work for the arm64
platform. As a temporary measure, the source code and docker build scripts
have been lifted from the official images and are used to build locally.

Some additional modifications are made to reduce overall image size, these
are documented in docker/README.md

docker/streamline-src/vendor/symfony/string/CodePointString.php

@@ -0,0 +1,260 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\String;
+
+use Symfony\Component\String\Exception\ExceptionInterface;
+use Symfony\Component\String\Exception\InvalidArgumentException;
+
+/**
+ * Represents a string of Unicode code points encoded as UTF-8.
+ *
+ * @author Nicolas Grekas <p@tchwork.com>
+ * @author Hugo Hamon <hugohamon@neuf.fr>
+ *
+ * @throws ExceptionInterface
+ */
+class CodePointString extends AbstractUnicodeString
+{
+    public function __construct(string $string = '')
+    {
+        if ('' !== $string && !preg_match('//u', $string)) {
+            throw new InvalidArgumentException('Invalid UTF-8 string.');
+        }
+
+        $this->string = $string;
+    }
+
+    public function append(string ...$suffix): static
+    {
+        $str = clone $this;
+        $str->string .= 1 >= \count($suffix) ? ($suffix[0] ?? '') : implode('', $suffix);
+
+        if (!preg_match('//u', $str->string)) {
+            throw new InvalidArgumentException('Invalid UTF-8 string.');
+        }
+
+        return $str;
+    }
+
+    public function chunk(int $length = 1): array
+    {
+        if (1 > $length) {
+            throw new InvalidArgumentException('The chunk length must be greater than zero.');
+        }
+
+        if ('' === $this->string) {
+            return [];
+        }
+
+        $rx = '/(';
+        while (65535 < $length) {
+            $rx .= '.{65535}';
+            $length -= 65535;
+        }
+        $rx .= '.{'.$length.'})/us';
+
+        $str = clone $this;
+        $chunks = [];
+
+        foreach (preg_split($rx, $this->string, -1, \PREG_SPLIT_DELIM_CAPTURE | \PREG_SPLIT_NO_EMPTY) as $chunk) {
+            $str->string = $chunk;
+            $chunks[] = clone $str;
+        }
+
+        return $chunks;
+    }
+
+    public function codePointsAt(int $offset): array
+    {
+        $str = $offset ? $this->slice($offset, 1) : $this;
+
+        return '' === $str->string ? [] : [mb_ord($str->string, 'UTF-8')];
+    }
+
+    public function endsWith(string|iterable|AbstractString $suffix): bool
+    {
+        if ($suffix instanceof AbstractString) {
+            $suffix = $suffix->string;
+        } elseif (!\is_string($suffix)) {
+            return parent::endsWith($suffix);
+        }
+
+        if ('' === $suffix || !preg_match('//u', $suffix)) {
+            return false;
+        }
+
+        if ($this->ignoreCase) {
+            return preg_match('{'.preg_quote($suffix).'$}iuD', $this->string);
+        }
+
+        return \strlen($this->string) >= \strlen($suffix) && 0 === substr_compare($this->string, $suffix, -\strlen($suffix));
+    }
+
+    public function equalsTo(string|iterable|AbstractString $string): bool
+    {
+        if ($string instanceof AbstractString) {
+            $string = $string->string;
+        } elseif (!\is_string($string)) {
+            return parent::equalsTo($string);
+        }
+
+        if ('' !== $string && $this->ignoreCase) {
+            return \strlen($string) === \strlen($this->string) && 0 === mb_stripos($this->string, $string, 0, 'UTF-8');
+        }
+
+        return $string === $this->string;
+    }
+
+    public function indexOf(string|iterable|AbstractString $needle, int $offset = 0): ?int
+    {
+        if ($needle instanceof AbstractString) {
+            $needle = $needle->string;
+        } elseif (!\is_string($needle)) {
+            return parent::indexOf($needle, $offset);
+        }
+
+        if ('' === $needle) {
+            return null;
+        }
+
+        $i = $this->ignoreCase ? mb_stripos($this->string, $needle, $offset, 'UTF-8') : mb_strpos($this->string, $needle, $offset, 'UTF-8');
+
+        return false === $i ? null : $i;
+    }
+
+    public function indexOfLast(string|iterable|AbstractString $needle, int $offset = 0): ?int
+    {
+        if ($needle instanceof AbstractString) {
+            $needle = $needle->string;
+        } elseif (!\is_string($needle)) {
+            return parent::indexOfLast($needle, $offset);
+        }
+
+        if ('' === $needle) {
+            return null;
+        }
+
+        $i = $this->ignoreCase ? mb_strripos($this->string, $needle, $offset, 'UTF-8') : mb_strrpos($this->string, $needle, $offset, 'UTF-8');
+
+        return false === $i ? null : $i;
+    }
+
+    public function length(): int
+    {
+        return mb_strlen($this->string, 'UTF-8');
+    }
+
+    public function prepend(string ...$prefix): static
+    {
+        $str = clone $this;
+        $str->string = (1 >= \count($prefix) ? ($prefix[0] ?? '') : implode('', $prefix)).$this->string;
+
+        if (!preg_match('//u', $str->string)) {
+            throw new InvalidArgumentException('Invalid UTF-8 string.');
+        }
+
+        return $str;
+    }
+
+    public function replace(string $from, string $to): static
+    {
+        $str = clone $this;
+
+        if ('' === $from || !preg_match('//u', $from)) {
+            return $str;
+        }
+
+        if ('' !== $to && !preg_match('//u', $to)) {
+            throw new InvalidArgumentException('Invalid UTF-8 string.');
+        }
+
+        if ($this->ignoreCase) {
+            $str->string = implode($to, preg_split('{'.preg_quote($from).'}iuD', $this->string));
+        } else {
+            $str->string = str_replace($from, $to, $this->string);
+        }
+
+        return $str;
+    }
+
+    public function slice(int $start = 0, ?int $length = null): static
+    {
+        $str = clone $this;
+        $str->string = mb_substr($this->string, $start, $length, 'UTF-8');
+
+        return $str;
+    }
+
+    public function splice(string $replacement, int $start = 0, ?int $length = null): static
+    {
+        if (!preg_match('//u', $replacement)) {
+            throw new InvalidArgumentException('Invalid UTF-8 string.');
+        }
+
+        $str = clone $this;
+        $start = $start ? \strlen(mb_substr($this->string, 0, $start, 'UTF-8')) : 0;
+        $length = $length ? \strlen(mb_substr($this->string, $start, $length, 'UTF-8')) : $length;
+        $str->string = substr_replace($this->string, $replacement, $start, $length ?? \PHP_INT_MAX);
+
+        return $str;
+    }
+
+    public function split(string $delimiter, ?int $limit = null, ?int $flags = null): array
+    {
+        if (1 > $limit ??= \PHP_INT_MAX) {
+            throw new InvalidArgumentException('Split limit must be a positive integer.');
+        }
+
+        if ('' === $delimiter) {
+            throw new InvalidArgumentException('Split delimiter is empty.');
+        }
+
+        if (null !== $flags) {
+            return parent::split($delimiter.'u', $limit, $flags);
+        }
+
+        if (!preg_match('//u', $delimiter)) {
+            throw new InvalidArgumentException('Split delimiter is not a valid UTF-8 string.');
+        }
+
+        $str = clone $this;
+        $chunks = $this->ignoreCase
+            ? preg_split('{'.preg_quote($delimiter).'}iuD', $this->string, $limit)
+            : explode($delimiter, $this->string, $limit);
+
+        foreach ($chunks as &$chunk) {
+            $str->string = $chunk;
+            $chunk = clone $str;
+        }
+
+        return $chunks;
+    }
+
+    public function startsWith(string|iterable|AbstractString $prefix): bool
+    {
+        if ($prefix instanceof AbstractString) {
+            $prefix = $prefix->string;
+        } elseif (!\is_string($prefix)) {
+            return parent::startsWith($prefix);
+        }
+
+        if ('' === $prefix || !preg_match('//u', $prefix)) {
+            return false;
+        }
+
+        if ($this->ignoreCase) {
+            return 0 === mb_stripos($this->string, $prefix, 0, 'UTF-8');
+        }
+
+        return 0 === strncmp($this->string, $prefix, \strlen($prefix));
+    }
+}