[FEATURE REQUEST] Cleanup Assets

I think, a button to remove all the un-used assets, in a project, is extremely needed. The current way of doing it, is to migrate all the levels to a new project. It would just save so much time, especially with my current project which currently has 40gb of assets. Barely half of which, im going to use.

why not just have them all in a temp folder then as you use them move them to their proper place in your project. or only import what you need.