Swish: Handle specific errors and edge cases

[cesarcosta99]

This involves identifying and managing errors and edge cases related to Swish. The goal is to ensure robust error handling, preventing unexpected failures and providing clear messaging to users.

• Test all failure scenarios outlined in Stripe's testing instructions and ensure proper error handling.
  • Implement appropriate user-facing error messages for common failure cases (e.g., insufficient funds, authentication failure).
  • Ensure errors and status are surfaced correctly in the checkout flow and order management.
  • Log errors for debugging and support purposes, if you see fit.
• Identify and document in this issue any edge cases encountered during development.
  • Implement necessary fixes for critical edge cases before the payment method rollout.
• Add unit tests for key error handling scenarios.