Add support for Cluster update settings API

[Kargo]

Is your feature request related to a problem? Please describe.
I cannot complete my migration from NEST to Elastic.Clients.Elasticsearch because the Cluster update settings API is missing from the new client.

The following snippet is valid using NEST 7.17.5:

var settingsResponse = await _client.Cluster.PutSettingsAsync(
    descriptor => descriptor.Persistent(
        settings => settings.Add(
            "action.auto_create_index",
            value: false)));

Describe the solution you'd like
A cluster put settings method is available on the Elastic.Clients.Elasticsearch client with comparable syntax to the existing method from the NEST client.

Describe alternatives you've considered

• Keep using NEST client until Cluster update settings API is supported
• Implement custom client specifically to handle cluster setting updates