Move image zooming back to unvendorized lib (#6980)

* Move image zooming back to unvendorized lib

* refactor

* perf: Avoid mounting zoom dialog until interacted

* Add captions to lightbox

* lightbox

app/editor/index.tsx

@@ -618,6 +618,13 @@ export class Editor extends React.PureComponent<
    */
   public getHeadings = () => ProsemirrorHelper.getHeadings(this.view.state.doc);
 
+  /**
+   * Return the images in the current editor.
+   *
+   * @returns A list of images in the document
+   */
+  public getImages = () => ProsemirrorHelper.getImages(this.view.state.doc);
+
   /**
    * Return the tasks/checkmarks in the current editor.
    *