API route to retrieve all view entities in database

[rmainwork]

This ticket implements the R part of CRUD (or GET /api/user/views). This API route should return only the views belonging to the current user. It should do this by inspecting the currently authenticated user and querying the database for view.eppn == user.eppn.

To complete this ticket, we'll probably need:

• A ViewService with a getByUser method or similar. Into that method we can provide the user EPPN
• Also been wondering about creating some kind of request-scoped CURRENT_USER token to @Inject into controller actions so that we can @Inject(CURRENT_USER) both here and (potentially) in other places if we want to later, rather than injecting Request and inspecting req.user each time.

[jonseitz]

As with #438, this won't be done unless/until our users ask for it