Add Support of fido based algorithms in sshd ( OpenSSH Server)

[forrest96er]

Could you add support for FIDO-backed public key authentication in the OpenSSH Server (sshd)?
This includes the following algorithms:

• sk-ssh-ed25519-cert-v01@openssh.com
• sk-ecdsa-sha2-nistp256-cert-v01@openssh.com
• sk-ssh-ed25519@openssh.com
• sk-ecdsa-sha2-nistp256@openssh.com

The implementation should be straightforward.

Please add the following configurations to sshd_config to indicate the supported implementations:

• PubkeyAuthOptions

• PubkeyAcceptedAlgorithms
  ssh-ed25519-cert-v01@openssh.com,
  ecdsa-sha2-nistp256-cert-v01@openssh.com,
  ecdsa-sha2-nistp384-cert-v01@openssh.com,
  ecdsa-sha2-nistp521-cert-v01@openssh.com,
  sk-ssh-ed25519-cert-v01@openssh.com,
  sk-ecdsa-sha2-nistp256-cert-v01@openssh.com,
  rsa-sha2-512-cert-v01@openssh.com,
  rsa-sha2-256-cert-v01@openssh.com,
  ssh-ed25519,
  ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,
  sk-ssh-ed25519@openssh.com,
  sk-ecdsa-sha2-nistp256@openssh.com,
  rsa-sha2-512,rsa-sha2-256

[maertendMSFT]

Issue created here: #2237

The issue will be used to track this request.