Error handling

[johanjanssens]

Improve error handling by implementing: https://tools.ietf.org/html/rfc7807

Resources:

• https://blog.restcase.com/rest-api-error-handling-problem-details-response/
• https://www.javacodegeeks.com/2019/05/http-status-code-enough-tackling-web-apis-error-reporting.html
• https://apisyouwonthate.com/blog/creating-good-api-errors-in-rest-graphql-and-grpc
• https://jsonapi.org/format/#error-objects

Also investigate: https://github.com/paragonie/corner