[!!!][TASK] Remove path-based backend module registration

In prior versions of TYPO3 it was possible to access
a backend module via a custom script (index.php) in a folder configured by a configuration file (conf.php) which
held information about the module and the access rights
to it.

The logic is removed.

Resolves: #72405
Releases: master
Change-Id: I3c84f89278f7cea9849821744b9dd14632aaca62
Reviewed-on: https://review.typo3.org/45417


Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Daniel Goerz <ervaude@gmail.com>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Tested-by: Andreas Fernandez <typo3@scripting-base.de>