Find some crazy way to automatically test GetTestAnswerFromStdin.

[Sqeaky]

This accepts input from stdin so there are ways to send it input. The hard part will be fixing all those ways in CI on different platforms. Likely it will need to be a subprocess test and annoying pipe shenanigans will be required.

This is low priority right up until we need it.

And again "If we didn't test it, it didn't work" So this doesn't work and is currently a bug.