In httpRequest, validate response data based on only fields

[hawkeyexl]

Today, Doc Detective can validate an HTTP reponse body by checking for fields and values, but that isn't helpful when the values aren't known.

To support the use case of matching only the fields/structure of the response but not the field values, Doc Detective should provide a solution. Options:

• Add a wildcard keyword to match any value in the current responseData option. This would technically satisfy the need but may not be intuitive. Can't simply use an empty string because that could be a valid, non-greedy JSON value, as could any wildcard strings.
• Support validating the response body with a JSON schema, either from an OpenAPI spec or specified independently. This would be scalable using Ajv and would pave the way for future OpenAPI spec support.