c80e30684c
This ports the `lock_material` layer property to GPv3. For this, the `layer_index` is also required in `retrieve_editable_points` and `retrieve_editable_strokes` to choose strokes based on the `lock_material` property. In `retrieve_editable_elements` we now pass the `MutableDrawingInfo` to get both the `drawing` and `layer_index`. Pull Request: https://projects.blender.org/blender/blender/pulls/119913