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/Cargo.toml

@@ -126,6 +126,7 @@ uuid.workspace = true
 waker-fn = "1.2.0"
 lyon = "1.0"
 workspace-hack.workspace = true
+libc.workspace = true
 
 [target.'cfg(target_os = "macos")'.dependencies]
 block = "0.1"