When snapping keyframes in the Graph Editor, handles
that were set to free didn't move.
The issue was that the snapping code didn't set the handle position.
Instead it relied on the handle recalculation (`calchandleNurb_intern`) to do the job.
That code doesn't affect free handles though.
The fix is to also offset the handles in the snapping code. The handle recalculation
will still run for all the other handle types so that behavior isn't expected to change.
This does NOT change the behavior of bezier snapping in the 3D viewport.
Pull Request: https://projects.blender.org/blender/blender/pulls/123173
1070ae46fa