2.0.0

• Breaking Changes
  • PayPalNativePayments
    • Remove entire PayPalNativePayments module
  • PayPalWebPayments
    • Replace delegate pattern with completion handlers and Swift concurrency
      • Remove PayPalWebCheckoutDelegate and PayPalVaultDelegate
      • Remove start(request:) method that uses delegate callbacks
      • Remove vault(vaultRequest:) method that uses delegate callbacks
      • Add start(request:completion(PayPalWebCheckoutResult?, CoreSDKError?) -> Void) to PayPalWebCheckoutClient
      • Add vault(vaultRequest:completion(PayPalVaultResult?, CoreSDKError?) -> Void) to PayPalWebCheckoutClient
      • Add start(request:) async throws -> PayPalCheckoutResult
      • Add vault(vaultRequest:) async throws -> PayPalVaultResult
    • Update completion handler types to use Result instead of optional tuples
      • Change start completion from (PayPalWebCheckoutResult?, CoreSDKError?) to Result<PayPalWebCheckoutResult, CoreSDKError>
      • Change vault completion from (PayPalVaultResult?, CoreSDKError?) to Result<PayPalVaultResult, CoreSDKError>
  • CardPayments
    • Replace delegate pattern with completion handlers and Swift concurrency
      • Remove CardDelegate and CardVaultDelegate
      • Remove approveOrder(request:) method that uses delegate callbacks
      • Remove vault(vaultRequest:) method that uses delegate callbacks
      • Add approveOrder(request:completion:(CardResult?, CoreSDKError?) -> Void) to CardClient
      • Add vault(request:completion:(CardVaultResult?, CoreSDKError?) -> Void) to CardClient
      • Add approveOrder(request:) async throws -> CardResult
      • Add vault(vaultRequest:) async throws -> CardVaultResult
    • Update completion handler types to use Result instead of optional tuples
      • Change approveOrder completion from (CardResult?, CoreSDKError?) to Result<CardResult, CoreSDKError>
      • Change vault completion from (CardVaultResult?, CoreSDKError?) to Result<CardVaultResult, CoreSDKError>
• CorePayments
  • Make CoreSDKError conform to Equatable
  • Rename NetworkingClientError to NetworkingError
  • Make NetworkingError enum and static constants public
• CardPayments
  • Make CardError enum and static constants public
  • Rename CardClientError to CardError
    • Add threeDSecureCanceledError to CardError
    • Add public static function isThreeDSecureCanceled(Error) to CardError to distinguish cancellation error from threeDSecure verification
    • Make CardError public to expose cancellation error handling helper
• PayPalWebPayments
  • Rename PayPalWebCheckoutClientError to PayPalError
  • Add .checkoutCanceledError and vaultCanceledError to PayPalError
  • Add public static functions isCheckoutCanceled(Error) and isVaultCanceled(Error) to PayPalError to distinguish cancellation errors in PayPal flows.
  • Make PayPalError public to expose cancellation error handling helpers
  • Make PayPalError enum and static constants public