Fill context menu of Zed macOS dock icon with recent projects (#8952)

Fixes https://github.com/zed-industries/zed/issues/8416

Release Notes:

- Added recent projects into Zed's macOS dock icon context menu ([8416](https://github.com/zed-industries/zed/issues/8416))

---------

Co-authored-by: Kirill Bulatov <kirill@zed.dev>

crates/gpui/src/platform/test/platform.rs

@@ -241,6 +241,10 @@ impl Platform for TestPlatform {
 
     fn set_menus(&self, _menus: Vec<crate::Menu>, _keymap: &Keymap) {}
 
+    fn add_recent_documents(&self, _paths: &[PathBuf]) {}
+
+    fn clear_recent_documents(&self) {}
+
     fn on_app_menu_action(&self, _callback: Box<dyn FnMut(&dyn crate::Action)>) {}
 
     fn on_will_open_app_menu(&self, _callback: Box<dyn FnMut()>) {}