Custom response status code

[keinu]

What did you implement:

_Implementing Issue:_ #2281

How did you implement it:

This PR makes the default 200 response as a variable that can be overridden by specifying a value in event.http.response.statusCode it will update the default response code with this setting.

How can we verify it:

When setting a custom response code such as

    events:
      - http:
          integration: lambda
          path: download/{document}
          method: get
          response:
            statusCode: 302
            headers:
              Location: "integration.response.body.url"

A get request to /download/whatevs should return a 302 HTTP code with the appropriate response value in the Location header

Todos:

• Write tests
• Write documentation
• Fix linting errors
• Make sure code coverage hasn't dropped
• Provide verification config/commands/resources
• Change ready for review message below

_Is this ready for review?:_ YES

[flomotlik]

This was resolved with #2014 , thanks for submitting the PR