Feature: #108975 - Add configuration provider for Extbase class configuration 

See forge#108975

Description 

Extbase class configuration (persistence mapping) is now exposed in the backend System > Configuration module. The module is available if the system extension typo3/cms-lowlevel is installed.

The displayed configuration reflects the configured mapping that Extbase uses at runtime. It is built by collecting and merging all EXT:my_extension/Configuration/Extbase/Persistence/Classes.php definitions from active packages.

Impact 

This is a read-only usability improvement. Developers and integrators can inspect and verify resolved Extbase persistence class mapping such as extension overrides in the backend, without having to dump configuration arrays or manually check each EXT:my_extension/Configuration/Extbase/Persistence/Classes.php file.