Re-factor how HCM highlight-filters are handled in the viewer components (PR 16593 follow-up)

This is something that I completely overlooked during review of PR 16593, since the idea is (obviously) that the viewer-components should be usable as-is without the user needing to manually pass in any *additional* parameters.

To support this we can very easily expose the current `FilterFactory`-instance on the `PDFPageProxy`-class[1], and if needed initialize the highlight-filters when initializing the page (again limited to the viewer-components).

src/display/api.js

@@ -1381,6 +1381,13 @@ class PDFPageProxy {
     return this._transport.getPageJSActions(this._pageIndex);
   }
 
+  /**
+   * @type {Object} The filter factory instance.
+   */
+  get filterFactory() {
+    return this._transport.filterFactory;
+  }
+
   /**
    * @type {boolean} True if only XFA form.
    */