quirks: sway does not damage surface beneath sub-surface, when unmapped

When unmapping a sub-surface, Sway <= 1.8 does not damage the surface
beneath the sub-surface.

https://github.com/swaywm/sway/issues/6960

The workaround is to manually damage the main surface. Previously,
this was done when exiting scrollback search, and after the ‘flash’
OSC. But other sub-surfaces, that may also be unmapped, did not.

This patch adds a quirk handler that does this, and calls it when:

* Exiting scrollback search
* Ending the ‘flash’ OSC
* Exiting unicode input mode
* Clearing URL labels
* Removing the scrollback position indicator

Closes #1335

search.c

@@ -15,6 +15,7 @@
 #include "input.h"
 #include "key-binding.h"
 #include "misc.h"
+#include "quirks.h"
 #include "render.h"
 #include "selection.h"
 #include "shm.h"
@@ -117,11 +118,6 @@ search_cancel_keep_selection(struct terminal *term)
 
     term_xcursor_update(term);
     render_refresh(term);
-
-    /* Work around Sway bug - unmapping a sub-surface does not damage
-     * the underlying surface */
-    term_damage_margins(term);
-    term_damage_view(term);
 }
 
 void