Bmeshview mods

This pull request introduces 

- (streamlined) UI
   -  name field without label (with tooltip)
   -  material selection field (avoid typing)

- in Beta options (N panel) 
  -  shade smooth switch.

- Code
  - random name button migrated permanently to the N panel, and repeated pressing of the button will generate new unique random names. (never pick existing, will always increment)

I do not know of a fast way to delete n vertices from a mesh object in one go, this makes dynamic mesh updates a little tricky without `bmesh_from_pydata` for the time being. 

I will make a branch specifically for experimenting further with alternatives to bmesh_from_pydata. `foreach` on tessfaces should make the mesh updates really fast.