Deprecation: #61829 - Deprecate config.classFile DBAL option

See Issue #61829

Description

The DBAL option config.classFile has been marked for deprecation, and will be removed with TYPO3 CMS 8.

Impact

Using config.classFile option will throw a deprecation message.

Affected Installations

Installations which use a user-defined DBAL database-handler.

Migration

Load the class using the autoloader.