Authentication Emulator should export / import mfaInfo field

[yuchenshi]

Now that #3173 is merged, the Auth Emulator should also export and import that field so it is not lost across exports.

[wokkaflokka]

If there are no takers champing at the bit, I can look into starting this one in the next week or so.

The more and more I use the emulator suite, the more I love it. Something tells me that I'll be wanting the ability to login with an MFA user via the emulator eventually, as well.

[christhompsongoogle]

wokkaflokka We love contributions from the community !