Flatten protobuf message namespace

* Remove `FromClient`/`FromServer` distinction.
* Remove `subscribe` concept - clients will need to handle
  unprompted messages from the server.

Co-Authored-By: Nathan Sobo <nathan@zed.dev>
e88f33851eMax Brunsfeld committed on 6/15/2021, 8:06:50 PMparent546ce14
5 files changedLine totals unavailable