Allow access to the body and query

[dr3]

Allows access to query, and body when it is available (in preValidation hook onwards)

Checklist

• run npm run test and npm run benchmark
• tests and/or benchmarks are included
• documentation is changed or added
• commit message and code follows the Developer's Certification of Origin
  and the Code of conduct

[mcollina]

Could you add tests for both the types and the code?

[mcollina]

Also docs

[mcollina]

lgtm

[Eomm]

I would release it as major version

[anthonyp-usafacts]

@dr3 just saw these features -- Thanks for your addition!