[IMPROVE] Subclass Selector Dropdown Menu

[j-schoch]

Improvement description

I would love it if when using AddTypeMenu attribute to show a custom display name in the SubclassSelector dropdown menu, it would support using paths in order to separate the dropdown contents into categories & submenus. Similar to the AddComponent menu and other Unity menu attributes like ContextMenu, AddMenu, CreateAssetMenu etc.

This would allow for a more scalable interface and organization in the editor when working with larger projects.

Thanks