Feature: #92522 - Show table and field names in ext:lowlevel

See forge#92522

Description

If the configuration ['BE']['debug'] is enabled and the current user is an administrator, the name of a DB table or DB field is appended to the select options in the "Full Search" module of ext:lowlevel.

Impact

This simplifies working with and debugging problems inside the full search of ext:lowlevel, as developers usually know the DB table and field names better than their labels configured in TCA.