- made working environment variables manager
From previous commits:
- renamed `ToastError` trait to `Toast`;
renamed its `toast_error` method to `toast`;
now `toast` method will not display button if toast's message is empty
- updated `game::run` function, now it prints running command
and supports `gamemoderun`
- added automatic `DXVK_ASYNC=1` setting for dxvk-async
- made preparations for environment settings
- now launcher hides when you launch the game
- now `Config::try_get_wine_executable` can return `Some("wine")`
- removed old wine and dxvk versions;
added new Wine-GE-Proton and GE-Proton builds