Removed defaul error handling
Extended new error Handling

- Return JSON Response for API calls
- Return View Responses for Frontend Errors
Changed Maintenance-Mode handler

- JSON response for API calls
- View for Frontend
Abort API when Screenshot can't be found
Return more info to client when API error accours

Return JSON Object to Client if an error accours
Added simple Validation to API

Should move Validation Rules to an Entity or Model. We need those rules in other places in the near future.