Merge pull request #3928 from nextcloud/downstream-17978

core/Command/Db/ConvertMysqlToMB4.php

core/register_command.php

lib/composer/composer/autoload_classmap.php

lib/composer/composer/autoload_static.php

lib/private/DB/Connection.php

lib/private/DB/ConnectionFactory.php

lib/private/DB/MDB2SchemaManager.php

lib/private/DB/MDB2SchemaReader.php

lib/private/Migration/ConsoleOutput.php

lib/private/Repair/Collation.php

tests/lib/DB/MDB2SchemaReaderTest.php

tests/lib/DB/SchemaDiffTest.php

tests/lib/Repair/RepairCollationTest.php