Uniform usage of FHIR module
Currently the conversion sometimes uses 'fhir4' as FHIR module, sometimes the in or -output module (after performing some checks) is used. This should be encapsulated and refactored.
- If the output module is a FHIR module, use this module.
- If the input module is a FHIR module, use this module. (Not sure)
- Else, use the 'current' FHIR module (on which the map converter is based on).