Refactor to make use of a common function for GetSubscriptionRelations and GetSubscriptionNotReadyRelations.

Hi,

Most of the code is common between GetSubscriptionRelations and
GetSubscriptionNotReadyRelations. Added a parameter to
GetSubscriptionRelations which could provide the same functionality as
the existing GetSubscriptionRelations and
GetSubscriptionNotReadyRelations. Attached patch has the changes for
the same. Thoughts?

Regards,
Vignesh