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 
viewport: parameters.viewport,
        linkService: parameters.linkService,
        downloadManager: parameters.downloadManager,
        imageResourcesPath: parameters.imageResourcesPath || "",
        renderInteractiveForms:
          typeof parameters.renderInteractiveForms === "boolean"
            ? parameters.renderInteractiveForms
            : true,
        svgFactory: new DOMSVGFactory(),
        annotationStorage:
          parameters.annotationStorage || new AnnotationStorage(),
        enableScripting: parameters.enableScripting,
        hasJSActions: parameters.hasJSActions,
        mouseState: parameters.mouseState || { isDown: false },
      });
      if (element.isRenderable) {
        const rendered = element.render();
        if (data.hidden) {
          rendered.style.visibility = "hidden";
        }
        if (Array.isArray(rendered)) {
          for (const renderedElement of rendered) {
            parameters.div.appendChild(renderedElement);
          }
        } else {
          if (element instanceof PopupAnnotationElement) {
            
            
            parameters.div.prepend(rendered);
          } else {