[!!!][TASK] Remove empty classes implementing AbstractTreeView

The tree class hierachie contains 3 empty classes, removed
by the patch:

* \TYPO3\CMS\Rtehtmlarea\ImageFolderTree
* rteFolderTree extends localPageTree in class.browse_links.php
* rtePageTree extends localFoltderTree in class.browse_links.php

Resolves: #55847
Related: #55830
Releases: 6.2
Change-Id: I5d0d92a484c37b6c2812f3350ab3f4dd3dfd15c8
Reviewed-on: https://review.typo3.org/27527
Tested-by: Tymoteusz Motylewski
Reviewed-by: Tymoteusz Motylewski
Reviewed-by: Frans Saris
Tested-by: Frans Saris
Reviewed-by: Markus Klein
Tested-by: Markus Klein