Deprecation: #63603 - FileController and FileListController overwriteExistingFiles changed to string value

See Issue #63603

Description

The GET/POST param to tell the FileController and FileListController whether to override a file or not switched from a bool value to a string with the possibilities of the \TYPO3\CMS\Core\Resource\DuplicationBehavior enumeration.

Impact

Extensions still using overwriteExistingFiles = 1 will throw a deprecation warning.

Affected Installations

All installations with extensions that use the BE upload functionality and supply the file override option.

Migration

Change the <input name="overwriteExistingFiles" value="1"> to <input name="overwriteExistingFiles" value="replace">.