Request form: Senior official fields need helper text to communicated required data formats

[AnnaGingle]

Story

Email * field does not communicate expected data formats. An error is not sufficient to meet Section 508 standards.

Email * error state does not include the error message in the screen reader/ ANDI output:

Acceptance Criteria

• [ ] Email * field has visual hint text Enter an email address in the required format, like name@example.com.. Match this design.
• [ ] Email error state for an empty field should have this screen reader output: `Who is the senior official for your organization? Email Enter an email address in the required format, like name@example.com. invalid entry, Enter an email address in the required format, like name@example.com, required.`

Additional Context

No response

Issue Links

Relates to Request form labels communicate required data format #2699

[AnnaGingle]

This issue will be completed as a part of issue #2848