Feature: #86967 - Allow fetching uid of a LazyLoadingProxy without loading the object first

See forge#86967

Description

A method getUid() has been added to class \TYPO3\CMS\Extbase\Persistence\Generic\LazyLoadingProxy which allows for fetching the uid of the proxied object without fetching the object data itself from the database.

Impact

The method getUid() can be used to fetch the uid of objects for a quick comparison with other objects of the same type which increases the performance of such comparisons a lot.