Upgraded sample code to 5.4 API level and updated the migration guide

Author: ok2c

samples/pom.xml

@@ -41,9 +41,9 @@
     <maven.compiler.source>1.8</maven.compiler.source>
     <maven.compiler.target>1.8</maven.compiler.target>
     <hc4.client.version>4.5.13</hc4.client.version>
-    <hc5.client.version>5.3</hc5.client.version>
+    <hc5.client.version>5.4.2</hc5.client.version>
     <jackson.version>2.12.6.1</jackson.version>
-    <asyncjson.version>0.2.0</asyncjson.version>
+    <asyncjson.version>0.4.0</asyncjson.version>
   </properties>
 
   <dependencies>

samples/src/main/java/org/apache/hc/client5/migration/examples/HttpClient5ClassicExample.java

@@ -36,7 +36,8 @@
 import org.apache.hc.client5.http.impl.io.PoolingHttpClientConnectionManager;
 import org.apache.hc.client5.http.impl.io.PoolingHttpClientConnectionManagerBuilder;
 import org.apache.hc.client5.http.protocol.HttpClientContext;
-import org.apache.hc.client5.http.ssl.SSLConnectionSocketFactoryBuilder;
+import org.apache.hc.client5.http.ssl.ClientTlsStrategyBuilder;
+import org.apache.hc.client5.http.ssl.TlsSocketStrategy;
 import org.apache.hc.core5.http.ClassicHttpRequest;
 import org.apache.hc.core5.http.ContentType;
 import org.apache.hc.core5.http.HttpEntity;
@@ -56,7 +57,7 @@ public class HttpClient5ClassicExample {
 
     public static void main(String... args) throws Exception {
         PoolingHttpClientConnectionManager connectionManager = PoolingHttpClientConnectionManagerBuilder.create()
-                .setSSLSocketFactory(SSLConnectionSocketFactoryBuilder.create()
+                .setTlsSocketStrategy((TlsSocketStrategy) ClientTlsStrategyBuilder.create()
                         .setSslContext(SSLContexts.createSystemDefault())
                         .setTlsVersions(TLS.V_1_3)
                         .build())

src/site/markdown/httpcomponents-client-5.4.x/migration-guide/migration-to-classic.md

@@ -43,7 +43,7 @@ There are also some important differences with URL normalization and encoding.
 
    ```java
    PoolingHttpClientConnectionManager connectionManager = PoolingHttpClientConnectionManagerBuilder.create()
-         .setSSLSocketFactory(SSLConnectionSocketFactoryBuilder.create()
+         .setTlsSocketStrategy((TlsSocketStrategy) ClientTlsStrategyBuilder.create()
                  .setSslContext(SSLContexts.createSystemDefault())
                  .setTlsVersions(TLS.V_1_3)
                  .build())