feat(user-sessions): add custom exceptions for game logic and enhance user session interaction

knockoutwhistweb/app/exceptions/NotInThisGameException.java

@@ -1,6 +1,6 @@
 package exceptions;
 
-public class NotInThisGameException extends RuntimeException {
+public class NotInThisGameException extends GameException {
     public NotInThisGameException(String message) {
         super(message);
     }