Reconnect button for remote projects (#12669)

Release Notes:

- N/A

---------

Co-authored-by: Max <max@zed.dev>

crates/collab_ui/src/collab_titlebar_item.rs

@@ -413,6 +413,17 @@ impl CollabTitlebarItem {
             );
         }
 
+        if self.project.read(cx).is_disconnected() {
+            return Some(
+                Button::new("disconnected", "Disconnected")
+                    .disabled(true)
+                    .color(Color::Disabled)
+                    .style(ButtonStyle::Subtle)
+                    .label_size(LabelSize::Small)
+                    .into_any_element(),
+            );
+        }
+
         let host = self.project.read(cx).host()?;
         let host_user = self.user_store.read(cx).get_cached_user(host.user_id)?;
         let participant_index = self