📍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>

private-class-data/src/test/java/com/iluwatar/privateclassdata/StewTest.java

@@ -53,7 +53,7 @@ public class StewTest {
    * Verify if mixing the stew doesn't change the internal state
    */
   @Test
-  public void testMix() {
+  void testMix() {
     final var stew = new ImmutableStew(1, 2, 3, 4);
     final var expectedMessage = "Mixing the immutable stew we find: 1 potatoes, "
         + "2 carrots, 3 meat and 4 peppers";