Remove focus filtering from gpui so all focus events result in focus-in and focus-out calls

Remove pane focused event in favor of focus_in at the workspace level
Added is_child to ViewContext to determine if a given view is a child of the current view
Fix issue where dock would get in a infinite loop when activated after dragging an item out of it
Fix issue where the last focused view in an item was not correctly refocused when a pane is focused after switching active tabs

Co-Authored-By: Mikayla Maki <mikayla@zed.dev>

crates/search/src/project_search.rs

@@ -200,6 +200,10 @@ impl View for ProjectSearchView {
                 .0
                 .insert(self.model.read(cx).project.downgrade(), handle)
         });
+
+        if cx.is_self_focused() {
+            self.focus_query_editor(cx);
+        }
     }
 }