Dial in the channel creating/renaming UI

* Ensure channel list is in a consistent state with no flicker while the
  channel creation / rename request is outstanding.
* Maintain selection properly when renaming and creating channels.
* Style the channel name editor more consistently with the non-editable
  channel names.

Co-authored-by: Mikayla <mikayla@zed.dev>

crates/rpc/src/proto.rs

@@ -146,7 +146,7 @@ messages!(
     (CopyProjectEntry, Foreground),
     (CreateBufferForPeer, Foreground),
     (CreateChannel, Foreground),
-    (CreateChannelResponse, Foreground),
+    (ChannelResponse, Foreground),
     (CreateProjectEntry, Foreground),
     (CreateRoom, Foreground),
     (CreateRoomResponse, Foreground),
@@ -262,7 +262,7 @@ request_messages!(
     (CopyProjectEntry, ProjectEntryResponse),
     (CreateProjectEntry, ProjectEntryResponse),
     (CreateRoom, CreateRoomResponse),
-    (CreateChannel, CreateChannelResponse),
+    (CreateChannel, ChannelResponse),
     (DeclineCall, Ack),
     (DeleteProjectEntry, ProjectEntryResponse),
     (ExpandProjectEntry, ExpandProjectEntryResponse),
@@ -305,7 +305,7 @@ request_messages!(
     (JoinChannel, JoinRoomResponse),
     (RemoveChannel, Ack),
     (RenameProjectEntry, ProjectEntryResponse),
-    (RenameChannel, Ack),
+    (RenameChannel, ChannelResponse),
     (SaveBuffer, BufferSaved),
     (SearchProject, SearchProjectResponse),
     (ShareProject, ShareProjectResponse),