editor: Add ToggleFocus action (#34495)

This PR adds action `editor: toggle focus` which focuses to last active
editor pane item in workspace.

Release Notes:

- Added `editor: toggle focus` action, which focuses to last active
editor pane item.

---------

Co-authored-by: Danilo Leal <daniloleal09@gmail.com>

crates/editor/src/actions.rs

@@ -425,6 +425,8 @@ actions!(
         FoldRecursive,
         /// Folds the selected ranges.
         FoldSelectedRanges,
+        /// Toggles focus back to the last active buffer.
+        ToggleFocus,
         /// Toggles folding at the current position.
         ToggleFold,
         /// Toggles recursive folding at the current position.