This patch restructures `object_convert_exec`, separated conversion calls for different source/target object type combination for better readability, keeping each route relatively simple and easy to navigate. Resolves #130653. ----------- NOTE: - Grease Pencil part is still WIP, the Grease Pencil -> Curves -> Mesh two stage conversion is not included in this new code yet. Pull Request: https://projects.blender.org/blender/blender/pulls/130668