Added `--run-game` and `--just-run-game` flags which can be used to run the game
1st will launch the game if launcher state is `Launch`.
Otherwise launcher window will appear
2nd will launch the game on `Launch` state,
as well as on `PredownloadAvailable` and `PatchAvailable(Patch::NotAvailable)`.
As well process stopping was changed by proper app exiting
by calling `relm4::main_application().quit()`