wayland: implement xdg-activation

wire/xdg_activation_v1.txt

@@ -0,0 +1,14 @@
+# requests
+
+msg destroy = 0 {
+
+}
+
+msg get_activation_token = 1 {
+    id: id(xdg_activation_token_v1),
+}
+
+msg activate = 2 {
+    token: str,
+    surface: id(wl_surface),
+}