fix(router): fix token fetch logic in complete authorize flow for three ds payments

[vspecky]

Type of Change

• Bugfix
• New feature
• Enhancement
• Refactoring
• Dependency updates
• Documentation
• CI/CD

Description

This PR fixes the issue where token data fetch from Redis was failing for 3DS payments going through the complete authorize flow. The issue being that the payment method was being taken from the request, where it may not be present. The solution was to add the payment method stored in the payment attempt as a fallback.

Additional Changes

• This PR modifies the API contract
• This PR modifies the database schema
• This PR modifies application configuration/environment variables

Motivation and Context

Certain connectors confirm their payments through the Complete Authorize flow when it comes to 3DS. To ensure that the token data fetch for this flow doesn't fail, we should be using the payment attempt as the fallback ground of truth for any missing data. This PR adds this fallback.

How did you test it?

3DS Payments with Cybersource (failing before, passing now)
Payment Confirmation:

Payment Redirection (Succeeding):

Checklist

• I formatted the code cargo +nightly fmt --all
• I addressed lints thrown by cargo clippy
• I reviewed the submitted code
• I added unit tests for my changes where possible
• I added a CHANGELOG entry if applicable