adds pixel drag mode to move tool

[mc-oofert]

Description

https://github.com/SpaiR/StrongDMM/assets/70376633/7dc0bbd3-6814-4424-a926-93f406ab4c2d

holding shift while dragging something with the move tool drags offsets instead

Type of change

• [ ] Minor changes or tweaks (quality of life stuff)
• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] This change requires a documentation update