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/doctrine/dbal/src/Driver/AbstractDB2Driver.php

@@ -0,0 +1,100 @@
+<?php
+
+namespace Doctrine\DBAL\Driver;
+
+use Doctrine\DBAL\Connection;
+use Doctrine\DBAL\Driver\API\ExceptionConverter as ExceptionConverterInterface;
+use Doctrine\DBAL\Driver\API\IBMDB2\ExceptionConverter;
+use Doctrine\DBAL\Exception as DBALException;
+use Doctrine\DBAL\Platforms\AbstractPlatform;
+use Doctrine\DBAL\Platforms\DB2111Platform;
+use Doctrine\DBAL\Platforms\DB2Platform;
+use Doctrine\DBAL\Schema\DB2SchemaManager;
+use Doctrine\DBAL\VersionAwarePlatformDriver;
+use Doctrine\Deprecations\Deprecation;
+
+use function assert;
+use function preg_match;
+use function version_compare;
+
+/**
+ * Abstract base implementation of the {@see Driver} interface for IBM DB2 based drivers.
+ */
+abstract class AbstractDB2Driver implements VersionAwarePlatformDriver
+{
+    /**
+     * {@inheritDoc}
+     */
+    public function getDatabasePlatform()
+    {
+        return new DB2Platform();
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * @deprecated Use {@link DB2Platform::createSchemaManager()} instead.
+     */
+    public function getSchemaManager(Connection $conn, AbstractPlatform $platform)
+    {
+        Deprecation::triggerIfCalledFromOutside(
+            'doctrine/dbal',
+            'https://github.com/doctrine/dbal/pull/5458',
+            'AbstractDB2Driver::getSchemaManager() is deprecated.'
+                . ' Use DB2Platform::createSchemaManager() instead.',
+        );
+
+        assert($platform instanceof DB2Platform);
+
+        return new DB2SchemaManager($conn, $platform);
+    }
+
+    public function getExceptionConverter(): ExceptionConverterInterface
+    {
+        return new ExceptionConverter();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function createDatabasePlatformForVersion($version)
+    {
+        if (version_compare($this->getVersionNumber($version), '11.1', '>=')) {
+            return new DB2111Platform();
+        }
+
+        Deprecation::trigger(
+            'doctrine/dbal',
+            'https://github.com/doctrine/dbal/pull/5156',
+            'IBM DB2 < 11.1 support is deprecated and will be removed in DBAL 4.'
+                . ' Consider upgrading to IBM DB2 11.1 or later.',
+        );
+
+        return $this->getDatabasePlatform();
+    }
+
+    /**
+     * Detects IBM DB2 server version
+     *
+     * @param string $versionString Version string as returned by IBM DB2 server, i.e. 'DB2/LINUXX8664 11.5.8.0'
+     *
+     * @throws DBALException
+     */
+    private function getVersionNumber(string $versionString): string
+    {
+        if (
+            preg_match(
+                '/^(?:[^\s]+\s)?(?P<major>\d+)\.(?P<minor>\d+)\.(?P<patch>\d+)/i',
+                $versionString,
+                $versionParts,
+            ) === 0
+        ) {
+            throw DBALException::invalidPlatformVersionSpecified(
+                $versionString,
+                '^(?:[^\s]+\s)?<major_version>.<minor_version>.<patch_version>',
+            );
+        }
+
+        return $versionParts['major'] . '.' . $versionParts['minor'] . '.' . $versionParts['patch'];
+    }
+}