feat: Validation 구현

Author: jay-so

src/main/java/calculator/Validation.java

@@ -0,0 +1,13 @@
+package calculator;
+
+import calculator.engine.enums.ConsoleMenu;
+
+public class Validation {
+    public static int checkConsoleNumber(int number){
+        if (number == ConsoleMenu.ONE.MenuNumber || number == ConsoleMenu.TWO.MenuNumber) {
+            return number;
+        } else {
+            throw new IllegalArgumentException("1번과 2번 중 하나를 선택해주세요.");
+        }
+    }
+}