All resources should be able to have a "Content Warning" field

[tpendragon]

Reasoning

It's been determined that Alma is not the right place to put content warnings for our bibliographic material, and it would be better to add it to the digitized item.

Ephemera has the following feature, which should be added to all resources:

All resources have the dropdown, but not the manual text entry - that text entry is what should be added here.

Acceptance Criteria

• When entering a content warning for a resource it should display that warning in the viewer.

First Step

Add a test.