wayland: implement xdg-toplevel-drag

wire/xdg_toplevel_drag_manager_v1.txt

@@ -0,0 +1,10 @@
+# requests
+
+msg destroy = 0 {
+
+}
+
+msg get_xdg_toplevel_drag = 1 {
+    id: id(xdg_toplevel_drag_v1),
+    data_source: id(wl_data_source),
+}

wire/xdg_toplevel_drag_v1.txt

@@ -0,0 +1,11 @@
+# requests
+
+msg destroy = 0 {
+
+}
+
+msg attach = 1 {
+    toplevel: id(xdg_toplevel),
+    x_offset: i32,
+    y_offset: i32,
+}