Hash route: Return an error if no content-type was provided

[ostcar]

If you use the hash-route in a wrong way, for example when no content-type is set or wrong request data is provided, the route returns with success=true and am empty hash. I think it would be better if there was an error message

$ curl --header "content-type: application/json" localhost:9004/internal/auth/hash -d '{"to_hash":"admin"}'
{"message":"Action handled successfully","success":true,"hash":""}

$ curl localhost:9004/internal/auth/hash -d '{"toHash":"admin"}'
{"message":"Action handled successfully","success":true,"hash":""}