The main issue was that the code was using
`foreach_editable_drawing_with_automask` which shouldn't have been
the case since there is no "masking" to be done when pasting strokes.
Additionally the code was computing the view position of every
pasted point and then computing the offset to move the points to the
mouse position.
Instead, we compute the center of the 3d bounds of the pasted strokes
and then project only the center to the view. From there we can offset
all the points to move them under the mouse cursor.
It's a bit weird to do this projection of the center to the view and
I believe we mainly do it to reuse the `DeltaProjectionFunc`.
There are cases where the projection of the center to the view will fail
which can lead to unexpected behavior on the user end. For now we
just leave the pasted strokes where they were copied from, which
isn't ideal. But this can be improved later.
Pull Request: https://projects.blender.org/blender/blender/pulls/134589
1a071ef755