Blender Git Loki

Fix GPencil part of [#36101] BSurface Throw an Error When Press "Add Surface"

gpencil_data_get_active and gpencil_data_get_active_v3d did not have consistent behavior when we had an active object, but not on any visible layer (the first would return the default scene gpd in this case, while the first was still returning active object's one). Now they both return scene's one.