Feature: Add a button in hammer that merges brushes with touching verticies

[Equalizer5118]

Which component should be improved?

Other

Describe your suggestion

As seen in Hammer++, if two brushes have matching edge vertices on one side, selecting both and pressing merge will combine the brushes on the edge they are touching. This will make optimizing world geometry much easier, as we will not have to redraw the brush and can just merge it.