Use YubiKey as MFA factor

[kchudy]

As a Defguard user, I want to register and use my YubiKey as a multi-factor authentication method, so that I can secure my account with a phishing-resistant hardware factor.

Acceptance criteria:

1. A user can enroll a YubiKey from their profile, and assign it a friendly name.
2. A user can register more than one security key (e.g., a primary and a backup).
3. During login, when MFA is required, the user is prompted to touch their YubiKey; successful assertion completes authentication.
4. A user can view, rename, and delete registered keys from their profile.

[filipslezaklab]

YK is being used as a FIDO2 client in this case. What we need to do is to expose current webauuthn endpoints (registration/login) as an enrollment and connect MFA method. In this case Master key from the module is being used and user presence (touch) is required to interact with it. Additionally we can store the key serial being used as an Key name so it cannot be registered twice for the user in core. We prob should test if it's possible to use this flow with YK/Hardware key that doesn't have user presence as webauthn itself is impossible there now but FIDO2 itself doesn't rly ban this type of interaction.