This PR implements the Cutter Tool for GPv3. The Cutter tool deletes
points in between intersecting strokes. New points are created at the
exact intersection points, so as a result the cutted strokes will fit
perfectly.
For feature parity, the tool follows the GPv2 behavior:
- The cutter tool works on all editable layers.
- Intersections are only detected for curves on the same layer,
so intersection of curves on _seperate_ layers are not handled.
Technical notes
The implementation uses the `compute_topology_change` function
created for the Hard Eraser. So at intersection points, point
attributes will be interpolated.
Pull Request: https://projects.blender.org/blender/blender/pulls/113953
Sietse Brouwer
4fbef3dc6b