feat(authenticator): Add passkey prompt UI

[mattcreaser]

• PR conforms to Pull Request guidelines.

Issue #, if available:

Description of changes:
Adds the UI for prompting users to create passkeys to the passwordless feature branch.

This UI isn't hooked up to anything yet, that will come in subsequent PRs.

The precise naming may change pending API review.

How did you test these changes?

• Unit tests, screenshot tests

Documentation update required?

• No
• Yes (Please include a PR link for the documentation update)

General Checklist

• Added Unit Tests
• Added Integration Tests
• Security oriented best practices and standards are followed (e.g. using input sanitization, principle of least privilege, etc)
• Ensure commit message has the appropriate scope (e.g fix(liveness): message, fix(authenticator): message, fix(all): message)

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.