app,app/internal/wm: [macOS] refresh context on display change

The NSViewGlobalFrameDidChangeNotification notification is documented to
be fired every time [NSOpenGLContext update] needs to be called.
However, the notification fails to fire on my setup when a window is
moved to a display with a different pixel scale, which leads to
incorrectly sized output.

This change gets rid of the notification and updates the context before
every frame.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

app/internal/wm/egl_x11.go

@@ -31,6 +31,10 @@ func (c *x11Context) Release() {
 	}
 }
 
+func (c *x11Context) Refresh() error {
+	return nil
+}
+
 func (c *x11Context) MakeCurrent() error {
 	c.Context.ReleaseSurface()
 	win, width, height := c.win.window()