The "is edit mode" checks in the draw module have been simplified
to just check the object mode. We need to be a bit more careful to
avoid retrieving the original mesh from a non-mesh object.
This commit improves the "get pre-modified mesh" function with
better comments and checks that reflect the relatively recent cases
where the original and evaluated geometry data types don't match.
It's always called with a mesh object too.
Pull Request: https://projects.blender.org/blender/blender/pulls/130850
fdb1bec6c8