refactor: make cancelEditItem method protected on EnhancedGrid class

Author: paodb

enhanced-grid-flow/src/main/java/com/vaadin/componentfactory/enhancedgrid/EnhancedGrid.java

@@ -327,7 +327,7 @@ protected void cancelEditWithCancelCallback(SerializableRunnable onCancelCallbac
     	}      
     }
 
-    private void cancelEditItem(T newEditItem, ContinueNavigationAction action, SerializableRunnable onCancelCallback) {
+    protected void cancelEditItem(T newEditItem, ContinueNavigationAction action, SerializableRunnable onCancelCallback) {
     	String text = getTranslation(CANCEL_EDIT_MSG_KEY);
     	String confirmText = getTranslation(CANCEL_EDIT_CONFIRM_BTN_KEY); 
     	String cancelText = getTranslation(CANCEL_EDIT_CANCEL_BTN_KEY);