feat: Add core interactors, mapper & bridge

[bthebladeprimer]

Summary

• Add CheckoutComponentsPaymentMethodsBridge for bridging payment method data between legacy and new architecture
• Add PaymentMethodMapper for mapping raw payment method config to domain models
• Add PrimerPaymentMethodType+ImageName extension for resolving payment method icons
• Add comprehensive test coverage for core interactors: card network detection, payment methods retrieval, card payment processing, input validation, and vaulted payment submission
• Add test mocks: MockHeadlessRepository, MockRawDataManager, MockClientSessionActionsModule

Context

PR 10 of 16 in the CheckoutComponents feature split. Depends on PR 9 (core services & navigation).

Notion tracker

Test plan

• CheckoutComponentsPaymentMethodsBridgeTests — verify payment method bridge data flow
• CardNetworkDetectionInteractorTests — verify card network detection logic
• GetPaymentMethodsInteractorTests — verify payment method retrieval
• ProcessCardPaymentInteractorTests — verify card payment processing
• SubmitVaultedPaymentInteractorTests — verify vaulted payment submission
• ValidateInputInteractorTests — verify input validation rules
• PaymentMethodMapperTests — verify mapping from raw config to domain models
• PrimerPaymentMethodTypeImageNameTests — verify image name resolution

[github-actions]

	Warnings
⚠️	> Pull Request size seems relatively large. If this Pull Request contains multiple changes, please split each into separate PR will helps faster, easier review.

Generated by 🚫 Danger Swift against 3871834