Make installer Deck/PC aware

[WallK]

AC

1. Installer should differentiate being run on Deck or PC
2. Installer should show the same options as it does right now if on Deck
3. On desktop: 3.1 Only "Home folder" and "Custom" install location options 3.2 Do not ask for Steam Deck custom controller profile installation 3.3 TBA

[MatthijsMarco]

Would this be based on hardware or on operating system type? If on hardware, it can take into account non-Steam Deck screen resolution, beefier GPU, standard controller profiles without trackpads and back buttons, no touch screen, etc. It would also cover systems running faux-SteamOS, like Bazzite and chimeraOS, on non-Steam Deck hardware. If based on operating system type it could not do that, but it could make less assumptions about paths/install locations. I'm assuming this would be easier to do by just checking if Game Mode is installed or not. There's probably other benefits that I can't think of. I would say basing it on hardware would give the best UX and give the most opportunities, but it might be difficult to implement. Maybe just a little option at the beginning could be enough (Deck/HTPC/PC?, target resolution?, etc.)