Create custom GraphQL/Apollo errors to throw to clients

[dfernandezm]

In resolverMap.ts, handleErrors:

//TODO: these errors contain lots of information in stacktrace, should be cut to minimum information
// https://www.apollographql.com/docs/apollo-server/data/errors/#custom-errors

• Stacktraces should be logged only on server and not sent to clients
• Have a handler that deals with custom errors sending specific codes for known ones
• Basic e2e test / unit test
• Manage in a single place the ErrorCodes, handleErrors, and custom errors thrown