show host in titlebar (#3072)

Release Notes:

- show host in the titlebar of shared projects
- clicking on faces in the titlebar will now always follow the person
(it used to toggle)
- clicking on someone in the channel panel will follow that person
- highlight the currently open project in the channel panel

- fixes a bug where sometimes following between workspaces would not
work

crates/client/src/user.rs

@@ -595,6 +595,10 @@ impl UserStore {
         self.load_users(proto::FuzzySearchUsers { query }, cx)
     }
 
+    pub fn get_cached_user(&self, user_id: u64) -> Option<Arc<User>> {
+        self.users.get(&user_id).cloned()
+    }
+
     pub fn get_user(
         &mut self,
         user_id: u64,