single click channel (#7596)

- Open channel notes and chat on channel click
- WIP
- Fix compile error
- Don't join live kit until requested
- Track in_call state separately from in_room



Release Notes:

- Improved channels: you can now be in a channel without joining the
audio call automatically

**or**

- N/A

---------

Co-authored-by: Nathan Sobo <nathan@zed.dev>

crates/rpc/proto/zed.proto

@@ -183,7 +183,12 @@ message Envelope {
         LspExtExpandMacroResponse lsp_ext_expand_macro_response = 155;
         SetRoomParticipantRole set_room_participant_role = 156;
 
-        UpdateUserChannels update_user_channels = 157; // current max
+        UpdateUserChannels update_user_channels = 157;
+
+        JoinChannel2 join_channel2 = 158;
+        JoinChannelCall join_channel_call = 159;
+        JoinChannelCallResponse join_channel_call_response = 160;
+        LeaveChannelCall leave_channel_call = 161; // current max
     }
 }
 
@@ -291,6 +296,7 @@ message Participant {
     ParticipantLocation location = 4;
     uint32 participant_index = 5;
     ChannelRole role = 6;
+    bool in_call = 7;
 }
 
 message PendingParticipant {
@@ -1033,6 +1039,22 @@ message JoinChannel {
     uint64 channel_id = 1;
 }
 
+message JoinChannel2 {
+    uint64 channel_id = 1;
+}
+
+message JoinChannelCall {
+    uint64 channel_id = 1;
+}
+
+message JoinChannelCallResponse {
+    LiveKitConnectionInfo live_kit_connection_info = 1;
+}
+
+message LeaveChannelCall {
+    uint64 channel_id = 1;
+}
+
 message DeleteChannel {
     uint64 channel_id = 1;
 }