customEventUnListener(ev) {
    this.enableElements();

    if (ev.detail && ev.detail.type === PostMessageEventNamesEnum.HANDSHAKE && this.onHandshakeCallback) {
      this.onHandshakeCallback(ev.detail.tabInfo);
    } else if (ev.detail && ev.detail.type === PostMessageEventNamesEnum.CUSTOM && this.onChildCommunication) {
      this.onChildCommunication(ev.detail.tabInfo);
    }
  }
Enable link/btn, which got disabled on clicking.
Note: works only when `data-tab-opener="child"` is used on the respective element
@param  {Object} ev - Event