This commit is a refactoring of code that has been located in the main
package. We introduce separate packages for the main application, jobs,
notifications, and request handlers.
Dependencies are injected from the main application, this will make
testing easier.
- remove the old code and its dependencies
- perform some refactoring and fix notifications
- add TODO tags for observed shortcomings
- rename voters.go to users.go
- implement health check for SMTP connection
- drop migration 2022052601_drop_unused_decisions_colums because it was implicitly part of an earlier migration
- add /health endpoint for database health check
- add tests for the health check endpoint
- add tests for middleware secureHeaders, logRequest and tryAuthenticate
- add models.UserModel.CreateUser method
