📍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>

arrange-act-assert/README.md

@@ -81,10 +81,10 @@ Then we write our unit tests according to Arrange/Act/Assert pattern. Notice the
 separated steps for each unit test.
 
 ```java
-public class CashAAATest {
+class CashAAATest {
 
   @Test
-  public void testPlus() {
+  void testPlus() {
     //Arrange
     var cash = new Cash(3);
     //Act
@@ -94,7 +94,7 @@ public class CashAAATest {
   }
 
   @Test
-  public void testMinus() {
+  void testMinus() {
     //Arrange
     var cash = new Cash(8);
     //Act
@@ -105,7 +105,7 @@ public class CashAAATest {
   }
 
   @Test
-  public void testInsufficientMinus() {
+  void testInsufficientMinus() {
     //Arrange
     var cash = new Cash(1);
     //Act
@@ -116,7 +116,7 @@ public class CashAAATest {
   }
 
   @Test
-  public void testUpdate() {
+  void testUpdate() {
     //Arrange
     var cash = new Cash(5);
     //Act