Injection of HttpClient.Builder for SseHttpClientTransportAutoConfiguration

[leesto82]

public class SseHttpClientTransportAutoConfiguration {
@bean
public List sseHttpClientTransports(...) {

	......
		HttpClientSseClientTransport.Builder transportBuilder = HttpClientSseClientTransport.builder(baseUrl)
			.sseEndpoint(sseEndpoint)
			.clientBuilder(HttpClient.newBuilder())
			.objectMapper(objectMapper);
	......
	}
	return sseTransports;
}

}

.clientBuilder(HttpClient.newBuilder())

SseHttpClientTransportAutoConfiguration needs to support custom injection of HttpClient.Builder to facilitate scenarios where SSL needs to be disabled

[quaff]

It's better to introduce an HttpClient.Builder customizer interface, similar to HttpRequest.Builder customizer in MCP SDK:

public interface McpHttpClientCustomizer {

	void customize(HttpClient.Builder builder);

}

see #3994

I'd like to contribute if the proposal is accepted.