Refactor the reupload of document on whiteboards

[hero101]

Description

The user can open an existing board A, copy some content including images, and paste it on their board B. That will not copy the documents to Whiteboard B's storage bucket but will still point to the document uploaded to board A. If board A's authorization changes, these documents are no longer readable. There has to be a check on every save of the whiteboard, to ensure all the files in the content are uploaded to the whiteboard's storage bucket. This story is about refactoring this function to be more efficient since it will be execute for every whiteboard save.

As a I want So that

Acceptance criteria

• [ ] The number of requests to the database is reduced

Additional Context

Screen shots / UX designs / data that are relevant.

Areas that will be affected

To be added during the refinement