SC | Fix new form submit

[Mottie]

Are you removing, renaming or moving a folder in this PR?

• [x] No, I'm not changing any folders (skip to TeamSites and delete the rest of this section)
• [ ] Yes, I'm removing, renaming or moving a folder

Did you change site-wide styles, platform utilities or other infrastructure?

• [x] No
• [ ] Yes, and I used the proxy-rewrite steps to test the injected header scenario

Summary

• (Summarize the changes that have been made to the platform)

  • Fix showing new Supplemental Claim form content on the review & submit page
  • Fix submit transformer to temporarily convert new VA evidence date to expected current values - will update once Lighthouse provides our new API
  • Add unit tests

• (If bug, how to reproduce)
• (What is the solution, why is this the solution)
• (Which team do you work for, does your team own the maintenance of this component?)

  Benefits Decision Reviews

• (If using a flipper, what is the end date of the flipper being required/success criteria being targeted)

Related issue(s)

https://github.com/department-of-veterans-affairs/va.gov-team/issues/95167

Testing done

• Describe what the old behavior was prior to the change
• Describe the steps required to verify your changes are working as expected
• Describe the tests completed and the results

  Added & updated unit tests

• _Exclusively stating 'Specs and automated tests passing' is NOT acceptable as appropriate testing
• Optionally, provide a link to your test plan and test execution records

Screenshots

N/A

What areas of the site does it impact?

Supplemental Claim new form (when feature toggle is enabled)

Acceptance criteria

Quality Assurance & Testing

• [x] I fixed|updated|added unit tests and integration tests for each feature (if applicable).
• [x] No sensitive information (i.e. PII/credentials/internal URLs/etc.) is captured in logging, hardcoded, or specs
• [x] Linting warnings have been addressed
• [ ] Documentation has been updated (link to documentation *if necessary)
• [ ] Screenshot of the developed feature is added
• [ ] Accessibility testing has been performed

Error Handling

• [ ] Browser console contains no warnings or errors.
• [ ] Events are being sent to the appropriate logging solution
• [ ] Feature/bug has a monitor built into Datadog or Grafana (if applicable)

Authentication

• [ ] Did you login to a local build and verify all authenticated routes work as expected with a test user

Requested Feedback

(OPTIONAL) What should the reviewers know in addition to the above. Is there anything specific you wish the reviewer to assist with. Do you have any concerns with this PR, why?