Merge Glint 2 into Ember Language Server

[machty]

This is a ways away, but so far I've received generally positive feedback, so I wanted to start sketching out what this might look like:

It would be nice to merge Glint 2 into Ember Language Server so that there's just one "Ember Language Server" that provides a nice unified tooling experience for Ember apps.

[NullVoxPopuli]

This isn't done :p