Diagnostics pane was not focusable with the mouse (#2506)

fixes
https://linear.app/zed-industries/issue/Z-1432/cant-cmd-w-an-empty-diagnostics-in-a-split-pane

Release Notes:

* Fixed a bug where the diagnostics pane could not be focused or closed
in certain circumstances.

crates/editor/src/editor.rs

@@ -7207,6 +7207,7 @@ pub enum Event {
     BufferEdited,
     Edited,
     Reparsed,
+    Focused,
     Blurred,
     DirtyChanged,
     Saved,
@@ -7258,8 +7259,10 @@ impl View for Editor {
     }
 
     fn focus_in(&mut self, _: AnyViewHandle, cx: &mut ViewContext<Self>) {
+        dbg!("Editor Focus in");
         if cx.is_self_focused() {
             let focused_event = EditorFocused(cx.handle());
+            cx.emit(Event::Focused);
             cx.emit_global(focused_event);
         }
         if let Some(rename) = self.pending_rename.as_ref() {