Breaking: #97151 - Remove "Database Relations" backend module

Description

The backend sub-module "Database Relations" within "DB Check" aims to provide information about potentially broken database relations. The information it gives is really sparse and barely helpful, also the whole module and its code received no meaningful updates in the past.

Due to this, the module has been removed.

Impact

The module has been removed. Links and stored bookmarks will not work anymore.

Affected installations

All TYPO3 installations are affected.

Migration

There is no migration available.