* Update tooltip to indicate support for multiple custom folder paths
* Remove migration step that worked around lack of multiple folder support
* Remove obsolete migration method
* Address linter warnings: build/include_what_you_use
* Add QStringList as requested on https://github.com/FreeCAD/FreeCAD/pull/19948/files#r1982267583
Start: Remove QML include
Start: Eliminate errors on unreadable images
Start: Ensure command succeeded
Start: Correct startup WB
Also re-enable the migrator, which was not the culprit.
Gui: Roll back unneeded NoneWorkbench changes
