elm_win: add elm_win_get()

it's frequently useful to be able to return the window object from
any object. this simplifies doing so for users

@feature

src/lib/elementary/efl_ui_win.c

@@ -6880,6 +6880,13 @@ _efl_ui_win_move_resize_start(Eo *obj EINA_UNUSED, Efl_Ui_Win_Data *sd, Efl_Ui_W
    return _win_move_resize_start(sd, mode);
 }
 
+EAPI Evas_Object *
+elm_win_get(Evas_Object *obj)
+{
+   EINA_SAFETY_ON_NULL_RETURN_VAL(obj, NULL);
+   return ecore_evas_data_get(ecore_evas_ecore_evas_get(evas_object_evas_get(obj)), "elm_win");
+}
+
 /* windowing specific calls - shall we do this differently? */
 
 EAPI Ecore_X_Window

src/lib/elementary/elm_win_legacy.h

@@ -1088,3 +1088,11 @@ EAPI void elm_win_aspect_set(Elm_Win *obj, double aspect);
  * by height.
  */
 EAPI double elm_win_aspect_get(const Elm_Win *obj);
+
+/**
+ * @brief Get the elm_win object from any child object
+ * 
+ * @return The elm_win, or @c NULL on failure
+ * @since 1.20
+ */
+EAPI Evas_Object *elm_win_get(Evas_Object *obj);