Add Mooneye GB emulator

[Mooneye GB](https://github.com/Gekkio/mooneye-gb) is "A Game Boy research project and emulator written in Rust. The main goals of this project are accuracy and documentation."

The author wrote the [Mooneye Test Suite](https://github.com/Gekkio/mooneye-test-suite) that's already part of this shootout.

Start by reviewing how the existing Mooneye Test Suite is integrated into the shootout and compare that with the Mooneye GB project linked in the issue. Add Mooneye GB to the emulator comparison, then verify that its results appear alongside the existing test-suite results.

Written by the indexing model from the issue text.