Clean up existing API code + Implement the rest of our REST API

[Austin2Shih]

There should only be two things:

• collections
• media

For each of these, check and test:

• _datalib
• _api
• _actions

Note You will likely want to refer to hack davis judging app code's backend to see what decent API code looks like. Please build on top of our decent practices by adding your own good practices. DO NOT treat the hack davis judging app code as if it's a complete source of truth since much of that code is not perfect. Just use it as a source of inspiration.

Also, please check on these parts in the order I listed (datalib, api, actions). Some of these things might not exist so create them.

For building out the REST API, follow this guide here for CRUD conventions, we are just doing POST, PUT, GET, DELETE