[feat: backend] add data queries to controller functions for `/haves` endpoints

[therealjustinbiele]

Description

As a developer, I want data sent to my server to be saved into a mongo database so that I can retrieve that information at a later time.

Acceptance Criteria

• Fill in the Have controller functions for the following actions
  • create a new Have
  • updating an existing Have by its ID (id should come from the route params)
  • delete / archiving a Have
  • getting a Have by its ID
  • getting a list of Haves

Testing Instructions

• Use Mongo Compass to determine if the Haves in the database are getting created / updated
• Ensure a User reference is saved with each creation
• Use the populate query to ensure the data populates the User reference