feat: Implement smooth resizing on X11 with _NET_WM_SYNC_REQUEST

Without smooth resizing, the window will appear to jitter when it is being
resized. This is because X11 completes the resize before the client gets a
chance to draw a new frame.

This is fixed by using the "sync" extension to ensure that the resize of the
X11 window is synchronized with the server.

Closes #2153

src/platform_impl/linux/x11/atoms.rs

@@ -48,6 +48,8 @@ atom_manager! {
     _NET_WM_NAME,
     _NET_WM_PID,
     _NET_WM_PING,
+    _NET_WM_SYNC_REQUEST,
+    _NET_WM_SYNC_REQUEST_COUNTER,
     _NET_WM_STATE,
     _NET_WM_STATE_ABOVE,
     _NET_WM_STATE_BELOW,