Introduce a new ToggleGraphicsProfiler command (#7607)

On macOS, this will enable or disable the Metal HUD at runtime. Note
that this only works when Zed is bundled because it requires to set the
`MetalHudEnabled` key in the Info.plist.

Release Notes:

- Added a new `ToggleGraphicsProfiler` command that can be used as an
action (or via the `Help -> Toggle Graphics Profiler` menu) to
investigate graphics performance.

crates/workspace/src/workspace.rs

@@ -118,6 +118,7 @@ actions!(
         ToggleRightDock,
         ToggleBottomDock,
         CloseAllDocks,
+        ToggleGraphicsProfiler,
     ]
 );
 
@@ -3395,6 +3396,7 @@ impl Workspace {
                     workspace.reopen_closed_item(cx).detach();
                 }),
             )
+            .on_action(|_: &ToggleGraphicsProfiler, cx| cx.toggle_graphics_profiler())
     }
 
     #[cfg(any(test, feature = "test-support"))]