As a Developer, I can specify which fields I want and which ones I do not want in the response, so that I have an efficient clean response to work with.

We want to support configuring this both on the definition, and as querystrings - in order to be very useful and handle developers use cases.

An important usecase is that a developer wants to prevent some fields from being returned. So if fields are not returned based on the definition - the querystring should NOT BE ABLE to make thoes fields be returned.

Acceptance Criteria:

• By default a response includes all fields, except metadata.
• I can specify which fields should be returned on the delivery endpoint configuration.
  • I can only specify fields at the "top" level of the response.
  • Or, I can specify which fields should be ommited.
  • If a field is marked as included and ommited, then it is ommited.
• I can also specify which fields can be returned or ommited via querystring parameter.
  • The response will then include the intersection of what is specified in configuration and in the querystring.
• I can specify fields in the same way on any of the reference resolvers.
  • I cannot influence the fields returned from reference resolvers on the querystring