Add getters for relation widgets (#3164)

These are available for the FormController as well, so this is just consistent and useful in some cases. Credit to @alxy

modules/backend/behaviors/RelationController.php

@@ -1603,4 +1603,22 @@ class RelationController extends ControllerBehavior
 
         return $this->makeConfig($config);
     }
+
+    /**
+     * Returns the manage widget used by this behavior.
+     *
+     * @return \Backend\Classes\WidgetBase
+     */
+    public function relationGetManageWidget() {
+        return $this->manageWidget;
+    }
+
+    /**
+     * Returns the view widget used by this behavior.
+     *
+     * @return \Backend\Classes\WidgetBase
+     */
+    public function relationGetViewWidget() {
+        return $this->viewWidget;
+    }
 }