Fix API return codes
Created by: Xylakant
The API returns 404 for almost all error states. This PR introduces more appropriate return codes which makes it easier for client developers to distinguish between the specific errors.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Created by: Xylakant
The API returns 404 for almost all error states. This PR introduces more appropriate return codes which makes it easier for client developers to distinguish between the specific errors.