(core): getPathDifference reinvents the wheel
Description
The function getPathDifference from core/tools/pathDifference
reinvents the wheel.
Proposal
Remove getPathDifference function and its file.
To my knowledge this function is only used once in modules/ui/qt/video/SCamera.cpp
. Replace it there by std::filesystem::relative. Check that this still works properly.
Outcomes
Less code, less bugs.