[Enhancement] Add Faces/Vertices to Existing Models

[marigi64]

I figure this is a rather big request, but would it be possible to implement a way to add new vertices/faces to existing models/Worldspawn as part of the face editor?

Some Goldsrc maps have missing faces on complex geometry due to being assigned to Worldspawn. For example some hanging rockets in hl1 (c2a5d).

A feature for adding faces/verts to Worldspawn could greatly help fix these problems.