Enhance HttpComponents5MessageSender.

* The clientFactory could be null, so this must be handled.
* AuthScope.ANY no longer exists, so we need a suitable value object to take its place.
* Polish documentation and javadocs to support the community.

Resolves #1357.

spring-ws-core/src/test/java/org/springframework/ws/transport/http/HttpComponents5MessageSenderTest.java

@@ -0,0 +1,33 @@
+package org.springframework.ws.transport.http;
+
+import java.time.Duration;
+
+import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
+import org.apache.hc.client5.http.impl.classic.HttpClientBuilder;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.*;
+
+class HttpComponents5MessageSenderTest {
+
+	@Test
+	void afterPropertiesSet_createHttpClient() throws Exception {
+		HttpComponents5MessageSender messageSender = new HttpComponents5MessageSender();
+		assertThat(messageSender.getHttpClient()).isNull();
+		Duration timeout = Duration.ofSeconds(1);
+		assertThatCode(() -> messageSender.setConnectionTimeout(timeout)).doesNotThrowAnyException();
+		messageSender.afterPropertiesSet();
+		assertThat(messageSender.getHttpClient()).isNotNull();
+	}
+
+	@Test
+	void afterPropertiesSet_httpClientAlreadySet() throws Exception {
+		CloseableHttpClient httpClient = HttpClientBuilder.create().build();
+		HttpComponents5MessageSender messageSender = new HttpComponents5MessageSender(httpClient);
+		Duration timeout = Duration.ofSeconds(1);
+		assertThatCode(() -> messageSender.setConnectionTimeout(timeout)).isInstanceOf(IllegalStateException.class);
+		messageSender.afterPropertiesSet();
+		assertThat(messageSender.getHttpClient()).isSameAs(httpClient);
+	}
+
+}