📍Use lombok, reformat, and optimize the code (#1560)

* Use lombok, reformat, and optimize the code

* Fix merge conflicts and some sonar issues

Co-authored-by: va1m <va1m@email.com>

async-method-invocation/src/main/java/com/iluwatar/async/method/invocation/App.java

@@ -24,8 +24,7 @@
 package com.iluwatar.async.method.invocation;
 
 import java.util.concurrent.Callable;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * This application demonstrates the async method invocation pattern. Key parts of the pattern are
@@ -55,10 +54,9 @@ import org.slf4j.LoggerFactory;
  * @see java.util.concurrent.CompletableFuture
  * @see java.util.concurrent.ExecutorService
  */
+@Slf4j
 public class App {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
-
   /**
    * Program entry point.
    */