Standardize api status codes and methods

[0phelia36]

TL;DR

Quick summary/list of your change(s) Errors no longer return status code 200. Endpoints that perform mutations are now POST requests rather than GET requests

What

What is affected by this PR?

• [X] API
• [ ] GUI
• [ ] Hardware Integration
• [ ] OS/Deployment
• [ ] Documentation
• [ ] Other (please describe in notes)

Testing

How was this tested?

• [ ] Locally Virtualized
• [ ] Raspberry Pi
• [X] With Hardware
• [ ] Other (please describe in notes)

Notes

How was your day?