Add visibility levels for products

[JBorrow]

Products should be able to have several visibility levels:

1. Public (as-is now)
2. Collaboration (logged-in users only)
3. Private (only the uploading user and administrators)

Required updates:

• [] Add literal to database
• [] Add endpoint to update this visibility level (should not be part of update as this would create a new version revision). Endpoint should allow for entire tree to be public or just an individual ID.
• [] Add UI elements demonstrating what visibility this is
• [] Add command-line functionality to modify visibility