gpui: Implement window_handle and display_handle for wayland platform (#28152)

This PR implements the previously unimplemented window_handle and
display_handle methods in the wayland platform. It also exposes the
display_handle method through the Window struct.

Release Notes:

- N/A

crates/gpui/src/window.rs

@@ -25,7 +25,7 @@ use derive_more::{Deref, DerefMut};
 use futures::FutureExt;
 use futures::channel::oneshot;
 use parking_lot::RwLock;
-use raw_window_handle::{HandleError, HasWindowHandle};
+use raw_window_handle::{HandleError, HasDisplayHandle, HasWindowHandle};
 use refineable::Refineable;
 use slotmap::SlotMap;
 use smallvec::SmallVec;
@@ -4428,6 +4428,14 @@ impl HasWindowHandle for Window {
     }
 }
 
+impl HasDisplayHandle for Window {
+    fn display_handle(
+        &self,
+    ) -> std::result::Result<raw_window_handle::DisplayHandle<'_>, HandleError> {
+        self.platform_window.display_handle()
+    }
+}
+
 /// An identifier for an [`Element`](crate::Element).
 ///
 /// Can be constructed with a string, a number, or both, as well