message: Introduce CustomWidgetCollection.add function. works as addCustomWidget
diff: @@ -60,6 +60,9 @@ export class CustomWidgetCollection {
  public get widgets(): Array<QuestionCustomWidget> {
  return this.widgetsValues;
  }
  + public add(widgetJson: any, activatedBy: string = "property") {
  + this.addCustomWidget(widgetJson, activatedBy);
  + }
  public addCustomWidget(widgetJson: any, activatedBy: string = "property") {
  var name = widgetJson.name;
  if (!name) {
  