Remote control: Allow modifying desktop panels and showing/hiding OS Windows using the kitten @ resize-os-window command

Also move the visibility toggle debounce into C code with a per OS
Window timer.

Fixes #8550

kitty/state.h

@@ -313,6 +313,11 @@ typedef struct {
     id_type last_focused_counter;
     CloseRequest close_request;
     bool is_layer_shell;
+    struct {
+        monotonic_t last_change_at;
+        bool set_visible;
+        id_type timer_id;
+    } debounce_visibility_changes;
 } OSWindow;