We have a great new command, spo site admin list, that I've been using a lot. However, there's an awkward issue when using the --asAdmin flag. Currently, the command outputs "id", "principalType", and "principalTypeString" as null when --asAdmin is used. This behavior is documented, but it seems illogical and cluttered.

If the API doesn't return these properties when --asAdmin is used, we should exclude them from the output entirely instead of showing null. This would make the output cleaner and more intuitive.

Currently, spo site admin list lacks default properties, making the terminal output unclear. I suggest using these properties for the default properties: Id, LoginName, Title, IsPrimaryAdmin.

We could also consider adding PrincipalTypeString, but we need to check if it doesn't make the output too wide.