Allow the Search Only and Admin API keys to be created

[huib-coalesce]

After creating a Typesense cluster, I want to be able to add a Search Only and Admin API key.

This PR allows the API keys to be created for a Typesense cluster:

resource "typesense_cluster_api_keys" "example" {
  cluster_id = "kvzb3qlwp27v19r4b"
}

Under the hood this performs:

curl --request POST \
     --url 'https://cloud.typesense.org/api/v1/clusters/<cluster-id>/api-keys' \
     --header 'X-TYPESENSE-CLOUD-MANAGEMENT-API-KEY: Us...Yk::6x...83' \
     --header 'Accept: application/json'

Which returns something like:

{
    "success": true,
    "api_keys": {
        "admin_key": "cBKqFPEcGRAS7RIKi3h3FuJbj4Q9Rprk",
        "search_only_key": "y7CFw2zEgu09FFhoDgLzC99j0RwKi0kL"
    }
}

The generated Admin key is configured with: Actions [*], Collections [*]
The generated Search Only key is configured with: Actions [documents:search], Collections [*]