New function creates a new service based on the provided context, the db interface and configuration.

AppData struct includes the required information by the API service to create an app, which are the name, the email of the admin, the session duration and the callback URL.

Config struct represents the configuration needed to init the service.

Service struct represents the service that is going to be started.

TokenRequest struct includes the required information by the API service to create a token, which is the email of the user.