Add ElasticsearchConfiguration for managing transport setup (#165)

Introduce `ElasticsearchConfiguration` to configure how the transport
connects and interacts with Elasticsearch, including support for Elastic
Cloud setups. This enables flexible connection options via URIs, Cloud
IDs, and various authentication mechanisms.

This makes it semantically cleaner to create a transport for
Elasticsearch.

Author: Mpdreamz

src/Elastic.Transport/Products/Elasticsearch/ElasticsearchConfiguration.cs

@@ -0,0 +1,43 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+using System;
+
+namespace Elastic.Transport.Products.Elasticsearch;
+
+/// <summary>
+/// Allows you to control how <see cref="ITransport{TConfiguration}"/> behaves and where/how it connects to Elasticsearch
+/// </summary>
+public record ElasticsearchConfiguration : TransportConfiguration
+{
+	/// <summary>
+	/// Creates a new instance of <see cref="ElasticsearchConfiguration"/>
+	/// </summary>
+	/// <param name="uri">The root of the Elastic stack product node we want to connect to. Defaults to http://localhost:9200</param>
+	public ElasticsearchConfiguration(Uri? uri = null)
+		: base(new SingleNodePool(uri ?? new Uri("http://localhost:9200")), productRegistration: ElasticsearchProductRegistration.Default ) { }
+
+	/// <summary>
+	/// Sets up the client to communicate to Elastic Cloud using <paramref name="cloudId"/>,
+	/// <para><see cref="CloudNodePool"/> documentation for more information on how to get your Cloud ID</para>
+	/// </summary>
+	public ElasticsearchConfiguration(string cloudId, BasicAuthentication credentials)
+		: base(new CloudNodePool(cloudId, credentials), productRegistration: ElasticsearchProductRegistration.Default) { }
+
+	/// <summary>
+	/// Sets up the client to communicate to Elastic Cloud using <paramref name="cloudId"/>,
+	/// <para><see cref="CloudNodePool"/> documentation for more information on how to get your Cloud ID</para>
+	/// </summary>
+	public ElasticsearchConfiguration(string cloudId, ApiKey credentials)
+		: base(new CloudNodePool(cloudId, credentials), productRegistration: ElasticsearchProductRegistration.Default) { }
+
+	/// <summary> Sets up the client to communicate to Elastic Cloud.</summary>
+	public ElasticsearchConfiguration(Uri cloudEndpoint, BasicAuthentication credentials)
+		: base(new CloudNodePool(cloudEndpoint, credentials), productRegistration: ElasticsearchProductRegistration.Default) { }
+
+	/// <summary> Sets up the client to communicate to Elastic Cloud. </summary>
+	public ElasticsearchConfiguration(Uri cloudEndpoint, ApiKey credentials)
+		: base(new CloudNodePool(cloudEndpoint, credentials), productRegistration: ElasticsearchProductRegistration.Default) { }
+
+}