OJ-3197 - Create NINo check handler

[barnabycollins]

Proposed changes

What changed

• New Lambda function written for NINo checking
• Some minor additions to lambdas/common
• /check-test endpoint added to NINo check API Gateway for testing purposes
• Unit tests for new function and utility function changes
• Integration tests added for new function

Why did it change

Step functions have been shown to have unsatisfactory performance, and are hard to test, debug and observe. Given that the NINo check logic is on a user's critical path to verifying their identity, we intend to replace the step functions with TypeScript Lambdas.

What's left to do (in other tickets)

• OJ-3201: Implement and test handling of multiple attempts, and retries (should be a small job)
• OJ-3202: Switch over APIGW /check endpoint to point to the Lambda; spin down step function resources & delete unused code

Issue tracking

• OJ-3197

Checklists

Environment variables or secrets

• No environment variables or secrets were added or changed

Other considerations

• Update README with any new instructions or tasks

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
99.2% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[Caitlin-cooling]

A mammoth effort Barnaby! Looks really good