Api 35595 registration numbers

[mchristiansonVA]

Summary

• This work is behind a feature toggle (flipper): NO
• Updates documentation examples to use a value of "999999999999" for registrationNumber attribute of 2122 and 2122a submissions, as well as corresponding validate calls.
• Updates tests where appropriate to accommodate value change.

Related issue(s)

-API-35595

Testing done

• New code is covered by unit tests
• Confirmed locally that documentation examples for affected endpoints reflect the update value for registrationNumber

Screenshots

What areas of the site does it impact?

526 documentation.

Acceptance criteria

• I fixed|updated|added unit tests and integration tests for each feature (if applicable).
• No error nor warning in the console.
• Events are being sent to the appropriate logging solution
• Documentation has been updated (link to documentation)
• No sensitive information (i.e. PII/credentials/internal URLs/etc.) is captured in logging, hardcoded, or specs
• Feature/bug has a monitor built into Datadog or Grafana (if applicable)
• If app impacted requires authentication, did you login to a local build and verify all authenticated routes work as expected
• I added a screenshot of the developed feature

[FonzMP]