feat(core): Added Reward PaymentMethod & CurrencyAuthKey for  Hyperswitch <> UCS Integration (#8767)

Co-authored-by: hyperswitch-bot[bot] <148525504+hyperswitch-bot[bot]@users.noreply.github.com>
Files to modify:


**unified_connector_service.rs**
  Modify existing code

**lib.rs**
  Modify existing code

**consts.rs**
  Modify existing code

**unified_connector_service.rs**
  Modify existing code

**transformers.rs**
  Modify existing code