Create/Update Category Get Controller to Fetch Topics by Date

[AlexDaGreat555]

Estimated Effort: M

Acceptance Criteria:

• controllers/category.js is updated to include GET controller action for categories filtered by posts
• Create unit tests for Controller action to see if it successfully returns correct results from API route

Create or update HTTP GET controller for NodeBB categories such that it is also able to filter by date

Key files: controllers/category.js
Dependencies: #25