[Passkey, suggestion] Should update user flow for "Forgot Password" for user with only 1 passkey

## Background:
- Device / Browser (OS version): Chrome on Mac
- Build: Version tag 2022-07-22.0

## Description:
For user with only 1 passkey, when they lost their passkey, they have no password to fallback to. They may not know that they need to click "Forgot password" to regain access.

## Steps to reproduce:
0. Use an app with passkey enabled.
1. Go to portal, Sign in with a user that has a passkey setup
2. Assume user has lost the passkey
3. They will be asked to enter password which they don't have.
4. User need to click "Forgot password" to proceed.

## Expected result:
Should updated user flow for "Forgot Password" when user lost the passkey. Say having a button "I have lost the passkey", allow them to re-verify via email to setup new passkey or setup a new password.

## Screenshot:

Start at the portal sign-in flow and the existing "Forgot Password" entry point described in the reproduction steps. Define the lost-passkey recovery flow, including email re-verification and choosing a new passkey or password; done means a user with one lost passkey can regain access without an existing password.

Written by the indexing model from the issue text.