Add requested content into Model

With requested content added into a model/db it allows the generation of pages such as requested content and such instead of transiently just sending the requests through. Can be beneficial for users to see requested content as well as admins.

The issue names no files, tests, or entry points. First trace how requests are currently passed through the application and where the model or database layer is defined. Clarify which requested content users and admins should see, and consider the work complete when that content is persisted and the corresponding pages are available.

Written by the indexing model from the issue text.