Set up 2FA process for DNCENG's Apple Developer account

[premun]

Moved from here: https://github.com/dotnet/core-eng/issues/15462

Context

As part of our Apple mobile app signing, we have an Apple Developer account (dotnetappledev@microsoft.com). This account is where we register our Apple devices and generate signing certificates.
To sign into this portal, 2FA is required:

• The 2FA requires an Apple devices that is signed into the same account (can be any device - MacOS/iOS/...)
• Once you try to log in, all devices signed into that account show a verification code

Currently, Premek and Ilya have devices set up for this but our team needs to have a way to go around this double point of failure in case they are not around.

Goals

We need to have a dedicated, secured OSX machine signed into that account somewhere outside of Helix but where we can remote desktop to it. This will be used by any member of our team who needs to access the developer portal
We need to have documentation for this 2FA sign-in available

[premun]

We have a dedicated machine DCI-MACPRO-01 for this now. The process is described here: https://dev.azure.com/dnceng/internal/_wiki/wikis/DNCEng%20Services%20Wiki/863/Apple-developer-portal-(2FA)