Strokes would lose their deform group values after moving them to a
different layer, because `vertex_group_names` weren't transferred to
the newly created `CurvesGeometry` inside `execute_realize_curve_tasks`.
This commit adds another version of `copy_vertex_group_names` for
Curves, and separates the duplicate code into `copy_vertex_group_name`,
which is used by both meshes and curves.
This also fixed strokes losing deform weights in multiple situations, such as:
- When performing a layer merge.
- When applying generative modifiers like Mirror or Array
Pull Request: https://projects.blender.org/blender/blender/pulls/142881
c95aa8dbd1