[fix] StepIndicator has hard-coded English status "[not] completed"

[werdnanoslen]

ReactUSWDS Version & USWDS Version:

react-uswds v9

Describe the bug

The StepIndicator has English "completed" and "not completed" hard-coded in its sr-only span, preventing i18n

To Reproduce Steps to reproduce the behavior:

1. Use screen reader on an otherwise non-English page
2. Scan a step indicator with mixed statuses
3. Hear English words despite translators' best work

Expected behavior

A new statusText prop to pass in for these words

Additional context #1742