Support K-Value store operations like [.values() - .keys()]

[Aymalla]

During the development of the data reconciliation application, one of the requirements was to get all the data that was submitted by a member; which is stored on a ccf kv-store; the "kv-store foreach" method was used to implement this requirement.

A better developer experience would be provided if the KV-Store included some features.

• Pagination mechanism
• Utility methods like
  • keys() to get all the stored keys as a list.
  • values() to get all the stored values as a list.