Cleaned and tidied code. Added basic firestore service support.

[emrothenberg]

• Added Firestore support: Introduced basic functionality for interacting with Firestore, enabling read and update operations through the Pyrebase4 library, with option to add create and delete for complete CRUD support.
• Code cleanup and refactoring: Improved code readability and maintainability by cleaning and tidying up existing code.

[nhorvath]

What were the material changes to the files that show completely changed? I prefer commits that use a linter for the first time to have no code changes so they can be ignored.

[emrothenberg]

1. Created a "services" module and moved all the services there (auth, database, storage),
2. Moved non-service classes to new module "types"
3. Created "utils" module to populate repeatedly used functions, since now not all elements are in the same file
4. Added a new service to include Firestore in services/firestore.py. This is the only functional change.
5. All changes after the first commit were only done to the firestore file, as well as updating the README to document functionality.