Correctly allow the AAGUID extension to be optional in Packed Attestation

[ErinvanderVeen]

The AAGUID extension for packed attestation is specifically marked as optional by the specification. This commit correctly reflects that in the implementation.

Resolves #173

[infinisil]

Implementation looks good, but can we also have a test case? Maybe @stephenjudkins has a JSON test case ready to use :D

We should also write release notes here already, this needs to increase the major version due to it being backwards-incompatible

[stephenjudkins]

Here's a registration response that should, I believe, exercise this issue. If it doesn't let me know and I'll check out the commit where we were reliably exercising this issue.

{
  "credential": {
    "extensions": {},
    "id": "vfEtvnc1AQrSir7_YemYlkW8V0lU7TDph0adJ1idgb8",
    "rawId": "vfEtvnc1AQrSir7_YemYlkW8V0lU7TDph0adJ1idgb8",
    "response": {
      "attestationObject": "o2NmbXRmcGFja2VkZ2F0dFN0bXSjY2FsZyZjc2lnWEYwRAIgF-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-N8qPmdTvHeL_0pklJiKU9t1ZUQf0JAsWTF_IiLqaK5iOCXDJ5IJfWaPRjFR0FXoRr--UGDMmsno10wWzAJBgNVHRMEAjAAMA4GA1UdDwEB_wQEAwIF4DAdBgNVHQ4EFgQU4ya71rpbUK4i_13TAUnXjTRmdFYwHwYDVR0jBBgwFoAU2jmj7l5rSw0yVb_vlWAYkK_YBwkwCgYIKoZIzj0EAwIDRwAwRAIgHkDSfA66vhTgSZffiMpP3G93qWLDcx6dCqZwHXhFIkYCIH7oDCPWl35DJkVWOPf1dUAlcrakMmHKthk78UG998dEaGF1dGhEYXRhWKSjN24DOxAOYYfBLybx16MskvRz-_qsWChC-u57I1w_AEUAAAAAD7m8vKDUQEK7sFWbwWMeKAAgvfEtvnc1AQrSir7_YemYlkW8V0lU7TDph0adJ1idgb-lAQIDJiABIVggqVKqgQBYpSqao2HzPgFsYdrjoIH2JADpwP14cnMYtPgiWCC3ELxU2Q9YVPiD3GobKUMVYHNevzDcBWvp41f2yTSoCw",
      "clientDataJSON": "eyJ0eXBlIjoid2ViYXV0aG4uY3JlYXRlIiwiY2hhbGxlbmdlIjoicUM2ejZ5TllydnM2Tlc0WkRTamNXdyIsIm9yaWdpbiI6Imh0dHBzOi8vbWVyY3VyeS5jb20vIiwidG9rZW5CaW5kaW5nIjpudWxsfQ",
      "transports": null
    },
    "type": "public-key"
  },
  "token": "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"
}