Fix mouse clicks on remote-open-folder UI (#19851)

Also change Zed's standard style to use
`.track_focus(&self.focus_handle(cx))`, instead of
`.track_focus(&self.focus_handle)`, to catch these kinds of errors more
easily in the future.

Release Notes:

- N/A

---------

Co-authored-by: Conrad <conrad@zed.dev>

crates/welcome/src/welcome.rs

@@ -72,7 +72,7 @@ impl Render for WelcomePage {
         h_flex()
             .size_full()
             .bg(cx.theme().colors().editor_background)
-            .track_focus(&self.focus_handle)
+            .track_focus(&self.focus_handle(cx))
             .child(
                 v_flex()
                     .w_80()