Pensions adjust helper text

[TaiWilkin]

Summary

On /medical/history/va-treatment/medical-centers, /va-treatment/medical-centers, /medical/history/federal-treatment/medical-centers, /employment/current/history, /employment/previous/history, the text "Enter all VA medical centers where you have received treatment" was not announced by screen readers when tabbing to the first input. This moves the secondary legend into the first as a span with styling to maintain the existing appearance, following the recommended action from platform.

Related issue(s)

department-of-veterans-affairs/va.gov-team#82852

Testing done

• Visit each of the routes listed above with a screenreader and confirm in the developer tools that the 'Enter all the...' text is within the page legend, that the text is read, and that the components appear the same as before.

Screenshots

	Before	After
VA Medical Centers
Federal Medical Centers
Current Employment
Previous Employment

What areas of the site does it impact?

Pension Benefits

Acceptance criteria

Quality Assurance & Testing

• I fixed|updated|added unit tests and integration tests for each feature (if applicable).
• No sensitive information (i.e. PII/credentials/internal URLs/etc.) is captured in logging, hardcoded, or specs
• 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