Additional quota error details when there is QuotaError.

[Proto definition ![GitHub](https://developers.google.com/site-assets/logo-github.svg)](https://github.com/googleapis/googleapis/blob/master/google/ads/googleads/v26/errors/errors.proto)

| Fields ||
|---|---|
| ## `rate_name` | `string` The high level description of the quota bucket. Examples are "Get requests for standard access" or "Requests per account". |
| ## `rate_scope` | `https://developers.google.com/google-ads/api/reference/rpc/v26/QuotaErrorDetails.QuotaRateScope` The rate scope of the quota limit. |
| ## `retry_delay` | `https://protobuf.dev/reference/protobuf/google.protobuf#duration` Backoff period that customers should wait before sending next request. |