add fine-grained resource for service perimeter resource

[modular-magician]

Fixes hashicorp/terraform-provider-google#4509.

In order to do this I had to make some changes to nested_query to allow it to add/remove an element of an array which is part of a nested object. I got it to work in this case by wrapping the object down the chain, so the patch request in this case would look like:

{
  "status": {
    "resources": [...]
  }
}

Notably, this doesn't merge the resources block into the status object that was returned from the API, but instead just wraps it. This works fine in this case because this API uses an update mask, so it can modify resources without changing anything else within status, but isn't future-proof if a similarly nested resource comes along that doesn't use an update mask.

Release Note Template for Downstream PRs (will be copied)

`google_access_context_manager_service_perimeter_resource`

Derived from GoogleCloudPlatform/magic-modules#3052