va-process-list: add ability to customize eyebrow status text

[powellkerry]

Chromatic

https://3500-process-list-eyebrow--65a6e2ed2314f7b8f98609d8.chromatic.com

Description

Adds a prop to va-process-list-item to allow the eyebrow status text to be customized. If no value is supplied the original static text will be displayed.

Closes department-of-veterans-affairs/vets-design-system-documentation#3500

QA Checklist

• [ x] Component maintains 1:1 parity with design mocks
• [ x] Text is consistent with what's been provided in the mocks
• [ x] Component behaves as expected across breakpoints
• [ x] Accessibility expert has signed off on code changes (if applicable. If not applicable provide reason why)
• [ x] Designer has signed off on changes (if applicable. If not applicable provide reason why)
• [ x] Tab order and focus state work as expected
• [ x] Changes have been tested against screen readers (if applicable. If not applicable provide reason why)
• [ x] New components are covered by e2e tests; updates to existing components are covered by existing test suite
• [ x] Changes have been tested in vets-website using Verdaccio (if applicable. If not applicable provide reason why)

Screenshots

Before:

After:

Acceptance criteria

• [ x] QA checklist has been completed
• [ x] Screenshots have been attached that cover desktop and mobile screens

Definition of done

• [ x] Documentation has been updated, if applicable
• [ x] A link has been provided to the originating GitHub issue (or connected to it via ZenHub)