Develop a comprehensive test suite

As the complexity of the project grows, we find that often adding a change to QEMU configurations breaks something else unintended. This pretty much happens every single change and is becoming unmanageable. We need an actual test plan:

1. A set of `.utm` files of various operating systems, architectures, and configurations.
2. A checklist of things to test for each one (mouse, sound, network, etc)
3. A matrix of configurations to check (Intel/M1 Mac, iPad, iOS of different versions, etc)

Then we can have a release sign-off that involves making sure everything is tested.