In the following spots a "MouseUp" eventName is being used, which does look inconsistent considering that the "Mouse Down"/"Mouse Enter"/"Mouse Exit" eventNames all have a space in them.
Is this inconsistency actually expected, or is it a simple typo? If the former, then a comment explaining *why* would be appropriate; otherwise we should just fix this :-)

 - https://github.com/mozilla/pdf.js/blob/25b84ce84c95ba06d1ee57e578672048269c39c1/src/display/annotation_layer.js#L806

 - https://github.com/mozilla/pdf.js/blob/25b84ce84c95ba06d1ee57e578672048269c39c1/src/display/annotation_layer.js#L945

 - https://github.com/mozilla/pdf.js/blob/25b84ce84c95ba06d1ee57e578672048269c39c1/src/display/annotation_layer.js#L1034

 - https://github.com/mozilla/pdf.js/blob/25b84ce84c95ba06d1ee57e578672048269c39c1/src/display/annotation_layer.js#L1168

/cc @calixteman 
(data.actions.Action || data.actions.MouseUp || data.actions.MouseDown) &&
      this.enableScripting &&
      this.hasJSActions
    ) {
      this._bindJSAction(link, data);
    } else {
      this._bindLink(link, "");
    }
    if (this.quadrilaterals) {
      return this._renderQuadrilaterals("linkAnnotation").map(
        (quadrilateral, index) => {
          const linkElement = index === 0 ? link : link.cloneNode();
          quadrilateral.appendChild(linkElement);
          return quadrilateral;
        }
      );
    }
    this.container.className = "linkAnnotation";
    this.container.appendChild(link);
    return this.container;
  }
  /**
   * Bind internal links to the link element.
   *
   * @private
   * @param {Object} link
   * @param {Object} destination
   * @memberof LinkAnnotationElement
   */
  _bindLink(link, destination) {