📍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>

multiton/src/main/java/com/iluwatar/multiton/App.java

@@ -23,8 +23,7 @@
 
 package com.iluwatar.multiton;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * Whereas Singleton design pattern introduces single globally accessible object the Multiton
@@ -38,10 +37,9 @@ import org.slf4j.LoggerFactory;
  * <p>In the enum implementation {@link NazgulEnum} is the multiton. It is static and mutable
  * because of the way java supports enums.
  */
+@Slf4j
 public class App {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
-
   /**
    * Program entry point.
    *