Select collab channel filter query upon focusing (#29383)

In the process of implementing this I learned that you can also hit
escape to clear the query which is a decent workaround, but I think this
behavior more closely matches expectations. For example when you run the
"focus search" actions, those select the query.

Release Notes:

- N/A

crates/collab_ui/src/collab_panel.rs

@@ -65,6 +65,15 @@ pub fn init(cx: &mut App) {
     cx.observe_new(|workspace: &mut Workspace, _, _| {
         workspace.register_action(|workspace, _: &ToggleFocus, window, cx| {
             workspace.toggle_panel_focus::<CollabPanel>(window, cx);
+            if let Some(collab_panel) = workspace.panel::<CollabPanel>(cx) {
+                collab_panel.update(cx, |panel, cx| {
+                    panel.filter_editor.update(cx, |editor, cx| {
+                        if editor.snapshot(window, cx).is_focused() {
+                            editor.select_all(&Default::default(), window, cx);
+                        }
+                    });
+                })
+            }
         });
         workspace.register_action(|_, _: &OpenChannelNotes, window, cx| {
             let channel_id = ActiveCall::global(cx)