Updating project while course staff is reviewing it could lead to an accidental approval of the update

If a client updates a project while a coordinator is looking at it, the coordinator could accidentally approve the update without reviewing it.

The approval and rejection buttons should show an error if the project has been modified since the page was loaded.

Do this using the updated_at date and pass this to the client (in a hidden field), and pass this back to the server when approving/rejecting. Show error if it doesn't match. Alternatively, use the "cache key".