APIT-2468: Resolve "Error: unexpected API Key "... resource" when creating SR confluent_api_key

[linouk23]

What

This PR resolves https://github.com/confluentinc/terraform-provider-confluent/issues/418.

Note

In short, the issue is isSchemaRegistryApiKey() was only expecting for srcm/v3 API version instead of any of srcm/v2 or srcm/v3.

The API Keys Mgmt API doesn't require api_version in the request and it does return resource.api_version=srcm/v2 by default:

➜  ✗ curl --request POST \
  --url https://api.confluent.cloud/iam/v2/api-keys \
  --header 'Authorization: Basic ...' \
  --header 'content-type: application/json' \
  --data '{"spec":{"display_name":"test2","owner":{"id":"sa-6zzw98"},"resource":{"id":"lsrc-kkg0rg","kind":"SchemaRegistry"}}}'
{
  "api_version": "iam/v2",
  "id": "OZSKBWUZFIF6QHUM",
  "kind": "ApiKey",
  "metadata": {
    "created_at": "2024-08-23T14:15:30.4238Z",
    "resource_name": "crn://api.confluent.cloud/organization=cc2d2db8-b889-4d72-8948-9d7cb37c6a9c/service-account=sa-6zzw98/api-key=OZSKBWUZFIF6QHUM",
    "self": "https://api.confluent.cloud/iam/v2/api-keys/OZSKBWUZFIF6QHUM",
    "updated_at": "2024-08-23T14:15:30.4238Z"
  },
  "spec": {
    "description": "",
    "display_name": "test2",
    "owner": {
      "api_version": "iam/v2",
      "id": "sa-6zzw98",
      "kind": "ServiceAccount",
      "related": "https://api.confluent.cloud/iam/v2/service-accounts/sa-6zzw98",
      "resource_name": "crn://api.confluent.cloud/organization=cc2d2db8-b889-4d72-8948-9d7cb37c6a9c/service-account=sa-6zzw98"
    },
    "resource": {
      "api_version": "srcm/v2", <------------
      "environment": "env-0j5orp",
      "id": "lsrc-kkg0rg",
      "kind": "SchemaRegistry",
      "related": "https://api.confluent.cloud/srcm/v2/schema-registries/lsrc-kkg0rg",
      "resource_name": "crn://api.confluent.cloud/organization=cc2d2db8-b889-4d72-8948-9d7cb37c6a9c/schema-registry=lsrc-kkg0rg"
    },
    "secret": "<REDACTED>"
  }
}

FWIW we can expect customers to hardcode the value for api_version from previous TF Provider versions as well so

1. We definitely need to accept both srcm/v2 and srcm/v3.
2. We can't hardcode srcm/v3 in TF state and DiffSurpressFunc will help us to resolve a potential TF drift: https://github.com/confluentinc/terraform-provider-confluent/blob/master/internal/provider/resource_api_key.go#L417-L423 (srcm/v2 / srcm/v3 in TF config but srcm/v2 / srcm/v3 in TF state).