Folders - Update a folder

Updates a folder's visibility (and optionally everything that's inside).

Builds upon https://github.com/oaeproject/Hilary/pull/1010
From a UI point of view, it would be better to split this up into 2 separate endpoints:

1. `updateFolder` endpoint that allows for the visibility (and metadata) of the folder to be updated
2. `updateFolderContentVisibility` endpoint that allows for the visibility of the items inside of a folder to be updated