feat(payment): add AcceptBusinessOrderQuotationUseCase
Implements TDD use case for accepting INFast business order quotations:
- Validates quotation document via IDocumentIntegrationPort.validateDocument()
- Accepts quotation via IDocumentIntegrationPort.acceptQuotation()
- Transitions business order status from PENDING_CONFIRMATION to QUOTATION_ACCEPTED
- Handles error cases: unknown token (BusinessOrderNotFoundException), already accepted order (ConflictException)