title_bar: Remove dependency on command_palette (#21006)

This PR removes the `title_bar` crate's dependency on the
`command_palette`.

The `command_palette::Toggle` action now resides at
`zed_actions::command_palette::Toggle`.

Release Notes:

- N/A

crates/zed/src/zed/app_menus.rs

@@ -146,7 +146,7 @@ pub fn app_menus() -> Vec<Menu> {
                 MenuItem::action("Back", workspace::GoBack),
                 MenuItem::action("Forward", workspace::GoForward),
                 MenuItem::separator(),
-                MenuItem::action("Command Palette...", command_palette::Toggle),
+                MenuItem::action("Command Palette...", zed_actions::command_palette::Toggle),
                 MenuItem::separator(),
                 MenuItem::action("Go to File...", workspace::ToggleFileFinder::default()),
                 // MenuItem::action("Go to Symbol in Project", project_symbols::Toggle),