Support for expressions (JSONPath, JMESPath or similar) when scrubbing.

[bjorkstromm]

Consider having a JSON like

{
  "id": "foo",
  "c": {
    "id": "bar"
  }
}

Now if I want to scrub id in the inner object c, there's no easy way to do it using only JSON. The below will scrub all properties with name id.

await VerifyJson(json).ScrubMember("id");

I propose adding support for JSONPath, JMESPath (or similar) expressions for more fine-grained control on which members to scrub. In the above example, if I only want the inner id scrubbed I could do something like:

await VerifyJson(json).ScrubMemberMatching("c.id");

[bjorkstromm]

Forgot to mention, but if you'd consider this a useful feature @SimonCropp, I'd be more than happy to try submitting a PR.

[SimonCropp]

happy to consider a PR