Switch to a new flow for advertising, sharing and joining worktrees

Now, when you open a local worktree, we immediately send an `OpenWorktree` message
to the server, telling it the name of the folder that you've opened, and the names of all the
collaborators (based on a `.zed.toml` file). The server responds with a unique id for the
worktree.

When starting share this local worktree, you now include this previously-assigned id
in the `ShareWorktree` message.

When joining a worktree, there is no longer a need to provide an access token. The access
is controlled by the set of "collaborator logins" that were provided when the worktree
was initially opened by the host.

zrpc/proto/zed.proto

@@ -35,6 +35,9 @@ message Envelope {
         ChannelMessageSent channel_message_sent = 30;
         GetChannelMessages get_channel_messages = 31;
         GetChannelMessagesResponse get_channel_messages_response = 32;
+        OpenWorktree open_worktree = 33;
+        OpenWorktreeResponse open_worktree_response = 34;
+        UnshareWorktree unshare_worktree = 35;
     }
 }
 
@@ -48,22 +51,30 @@ message Error {
     string message = 1;
 }
 
+message OpenWorktree {
+    string root_name = 1;
+    repeated string collaborator_logins = 2;
+}
+
+message OpenWorktreeResponse {
+    uint64 worktree_id = 1;
+}
+
 message ShareWorktree {
     Worktree worktree = 1;
 }
 
-message ShareWorktreeResponse {
+message ShareWorktreeResponse {}
+
+message UnshareWorktree {
     uint64 worktree_id = 1;
-    string access_token = 2;
 }
 
 message JoinWorktree {
     uint64 worktree_id = 1;
-    string access_token = 2;
 }
 
 message JoinWorktreeResponse {
-    uint64 worktree_id = 1;
     Worktree worktree = 2;
     uint32 replica_id = 3;
     repeated Peer peers = 4;
@@ -187,8 +198,9 @@ message User {
 }
 
 message Worktree {
-    string root_name = 1;
-    repeated Entry entries = 2;
+    uint64 id = 1;
+    string root_name = 2;
+    repeated Entry entries = 3;
 }
 
 message Entry {

zrpc/src/proto.rs

@@ -135,11 +135,13 @@ messages!(
     GetUsersResponse,
     JoinChannel,
     JoinChannelResponse,
+    JoinWorktree,
+    JoinWorktreeResponse,
     LeaveChannel,
     OpenBuffer,
     OpenBufferResponse,
-    JoinWorktree,
-    JoinWorktreeResponse,
+    OpenWorktree,
+    OpenWorktreeResponse,
     Ping,
     RemovePeer,
     SaveBuffer,
@@ -147,6 +149,7 @@ messages!(
     SendChannelMessageResponse,
     ShareWorktree,
     ShareWorktreeResponse,
+    UnshareWorktree,
     UpdateBuffer,
     UpdateWorktree,
 );
@@ -157,10 +160,12 @@ request_messages!(
     (JoinChannel, JoinChannelResponse),
     (OpenBuffer, OpenBufferResponse),
     (JoinWorktree, JoinWorktreeResponse),
+    (OpenWorktree, OpenWorktreeResponse),
     (Ping, Ack),
     (SaveBuffer, BufferSaved),
     (UpdateBuffer, Ack),
     (ShareWorktree, ShareWorktreeResponse),
+    (UnshareWorktree, Ack),
     (SendChannelMessage, SendChannelMessageResponse),
     (GetChannelMessages, GetChannelMessagesResponse),
 );
@@ -175,6 +180,7 @@ entity_messages!(
     JoinWorktree,
     RemovePeer,
     SaveBuffer,
+    UnshareWorktree,
     UpdateBuffer,
     UpdateWorktree,
 );