wayland: surface: add show/hide functionality

While the keyboard is running, it may want to automatically show or hide
itself depending on whether a text input is active. Add functions to
show and hide the surface by destroying and re-creating it.

Phosh's compositor, phoc, does not emit configure events in reaction to
a surface being committed with no buffer attached. The complicated
surface creation/destruction process is for compatibility with phoc.

src/wayland/dispatcher.rs

@@ -68,7 +68,7 @@ impl Dispatcher {
         };
 
         let disp = Surface::new(queue.clone(),
-                                &shm, &compositor, &layer_shell,
+                                &shm, compositor, layer_shell,
                                 frac_scale_man, vper, 185)?;
         let gfx = Graphics::new(disp);
         let gfx = Mutex::new(gfx);