Moved spring-mockito to testing-modules (#12476)

Co-authored-by: panagiotiskakos <panagiotis.kakos@libra-is.com>

testing-modules/spring-mockito/src/main/java/com/baeldung/NameService.java

@@ -0,0 +1,10 @@
+package com.baeldung;
+
+import org.springframework.stereotype.Service;
+
+@Service
+public class NameService {
+    public String getUserName(String id) {
+        return "Real user name";
+    }
+}