As an user of the API I want to get specific error messages in order to properly fix my code.
Problem:
The error message "wikibase-api-not-recognized-datatype": "A datatype was expected, but either missing or not recognized.", for an unrecognized datatype does not tell me:
- What the system thought was the value I was providing
- A comprehensive list of the valid values
Acceptance criteria:
- The error message tells me which (wrong or missing) value I provided and which values it considers valid.