hyperswitch

2daf55e1 - feat: add gateway abstraction layer for unified payment execution

feat: add gateway abstraction layer for unified payment execution Introduces a new gateway abstraction layer that provides a unified interface for executing payment operations through either direct connector integration or Unified Connector Service (UCS). This abstraction allows payment flows to use a consistent API regardless of the underlying execution path and enables multiple services to use the same interface without circular dependencies. Key additions: - Gateway execution path enum (Direct, UCS, Shadow UCS) - PaymentGateway trait for unified payment operation execution - Factory pattern for gateway creation - Router-specific gateway implementations - Support for shadow execution for migration scenarios