Add an endpoint to force the doc worker to fetch again the document from S3

[fflorent]

Describe the problem to be solved

When there is a problem with a document in production, I may want to bring changes to the document structure and push it on S3.

But there is no clear way to force the doc worker to fetch the new version from the remote storage.

Describe the solution you would like

Having an endpoint to wipe the cache would probably solve the issue, what do you think?