O3-5246: Test-cases for checking the new validation on POSTED state

[jayg2002]

This PR is to help provide all the scenarios needed for testing the validation in service layer for testing.

JIRA: https://openmrs.atlassian.net/browse/O3-5246

[jayg2002]

Hi @denniskigen @wikumChamith i am facing some issue in the test cases, which worked in past but not sure why its not working and i am unable to resolve the issue :

Error:

`
java.lang.IllegalArgumentException: Don't know how to handle: class sun.reflect.generics.reflectiveObjects.ParameterizedTypeImpl

at org.openmrs.util.Reflect.isSuperClass(Reflect.java:135)
at org.openmrs.util.Reflect.isSuperClass(Reflect.java:127)
at org.openmrs.util.Reflect.isCollectionField(Reflect.java:169)
at org.openmrs.aop.RequiredDataAdvice.recursivelyHandle(RequiredDataAdvice.java:307)
at org.openmrs.aop.RequiredDataAdvice.recursivelyHandle(RequiredDataAdvice.java:315)
at org.openmrs.aop.RequiredDataAdvice.recursivelyHandle(RequiredDataAdvice.java:231)
at org.openmrs.aop.RequiredDataAdvice.before(RequiredDataAdvice.java:128)
at org.springframework.aop.framework.adapter.MethodBeforeAdviceInterceptor.invoke(MethodBeforeAdviceInterceptor.java:57)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.aop.framework.adapter.MethodBeforeAdviceInterceptor.invoke(MethodBeforeAdviceInterceptor.java:58)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:241)
at com.sun.proxy.$Proxy225.saveBill(Unknown Source)
at org.openmrs.module.billing.impl.BillServiceImplTest.save_Bill_shouldThrowExceptionWhenModifyingLineItemQuantityAfterPartialPayment(BillServiceImplTest.java:500)
at java.lang.reflect.Method.invoke(Method.java:498)
at java.util.ArrayList.forEach(ArrayList.java:1259)
at java.util.ArrayList.forEach(ArrayList.java:1259)`

Can i get some assistance here as i am not able to progress further ?