Feature: Backend Auth

[bartbie]

Add auth to backend

TODO:

• [X] jwt/db logic
• [X] auth middleware & ctx
• [X] auth logic tests
• [X] auth router for login/signup/signout
• [x] refactor other routes to use auth middleware
• [ ] write & run e2e tests

[bartbie]

Added auth middleware to other routes, I need to run e2e tests and then it's ready to merge.