This adds a Game List configuration group box which is similar to yuzu's, with features including icon size setting, row 1/2 text, and ability to hide invalid titles (those without a valid SMDH). I also added a UI tab and moved the language and theme settings there.
Instead, we make a proper registry class and house it within the main
window, then pass it to whatever needs access to the loaded hotkeys.
This way, we avoid a global variable, and don't need to initialize a
std::map instance before the program can do anything.
