Set default name for mesh parts

When you upload a mesh to ROBLOX, it’ll be named MeshPart by default. Most people won’t even bother finding their mesh again and renaming it properly.

If the name of the file was chosen to be the name of the mesh asset by default, just like how Decals works (except you can change that before uploading), searching for old meshes would be easier, and people who have uploaded meshes won’t just have almost all of their mesh inventory filled with assets named “MeshPart”