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

shared/utils/ProsemirrorHelper.ts

@@ -171,6 +171,26 @@ export class ProsemirrorHelper {
     return comments;
   }
 
+  /**
+   * Iterates through the document to find all of the images.
+   *
+   * @param doc Prosemirror document node
+   * @returns Array<Node> of images
+   */
+  static getImages(doc: Node): Node[] {
+    const images: Node[] = [];
+
+    doc.descendants((node) => {
+      if (node.type.name === "image") {
+        images.push(node);
+      }
+
+      return true;
+    });
+
+    return images;
+  }
+
   /**
    * Iterates through the document to find all of the tasks and their completion state.
    *