Export Bug fixes

[spooksbit]

Addresses two issues from #31

1. When exporting the keys disappear from the UI.
   • This happened because the credentials list that was bound to the UI was being cleared. I don't think that needs to be cleared since the data is only being written out. Alternatively, and additional Add() could be included in the foreach loop as well.
2. When exporting, the password is not being serialized
   • This was happening because RetrievePassword() needs to be called to populate the password field prior to accessing it. See https://docs.microsoft.com/en-us/uwp/api/windows.security.credentials.passwordcredential.retrievepassword?view=winrt-22621#windows-security-credentials-passwordcredential-retrievepassword

[spooksbit]

Fwiw the second issue looks like an undocumented quirk in between Retrieve and RetrieveAll. From the looks of it, Retrieve really does populate the password field as if it's calling RetrievePassword implicitly, which is why GetKey works as expected. That does not seem to be the case for RetrieveAll, which has all the password fields unpopulated. MSDN doesn't really make this distinction from what I can see, so I guess they just figured "they're looking for something specific, so populate the password field for them" but that contradicts their statements around needing to call RetrievePassword in their documentation.

[FireCubeStudios]

Ok I am checking these changes out to confirm things work and will merge. I will probably do an earlier store release than the next feature release to address bugs only 👍

[FireCubeStudios]

Merged! Thanks