[Feature] Track history of changes in an APD

[thetif]

Description and related issues

We need to start auditing changes made to an APD. Add mongoose-patch-history to the APD model. This plugin tracks changes use json-patches, so it will be easier for the frontend to use. Create a virtual user to track the id of the user making the change.

This task is done when…

• [ ] mongoose-patch-history is added to the api
• [ ] mongoose-patch-history is configure to track all changes to a document and store the user id of the person making the change
• [ ] verify that the patch history is visible and retrievable
• [ ] document how to retrieve patch history
• [ ] store last edited by and last edited at
• [ ] create a migration to update the APD model
• [ ] updatedBy and updatedAt are recording the correct values on changes