[Request]: Add individual games/region to Steam

[bagusnl]

Is your request related to a problem?

No

How is the feature request related to the problem?

No response

Describe your proposed solution

Add a mean to add individual game/region to Steam "non-Steam" games, ala Heroic launcher https://github.com/Heroic-Games-Launcher/HeroicGamesLauncher.

Task list:

• Implement a command parser to go to a region and then launch it

Make sure it still works when another Collapse is already launched (either redirection or force multi-instance)

• Implement method to manage requested region into Steam's game library

Describe alternatives you've considered

Heroic's source code (typescript)

Add game
https://github.com/Heroic-Games-Launcher/HeroicGamesLauncher/blob/8bdee1383446d3b81e240a4300baaf337d48ec92/src/backend/shortcuts/nonesteamgame/nonesteamgame.ts#L206

Remove game
https://github.com/Heroic-Games-Launcher/HeroicGamesLauncher/blob/8bdee1383446d3b81e240a4300baaf337d48ec92/src/backend/shortcuts/nonesteamgame/nonesteamgame.ts#L387

Check if added
https://github.com/Heroic-Games-Launcher/HeroicGamesLauncher/blob/8bdee1383446d3b81e240a4300baaf337d48ec92/src/backend/shortcuts/nonesteamgame/nonesteamgame.ts#L498

Additional context

Requested by @/thathavonocyanite (310334103041998848) over at Discord https://discord.com/channels/1116150300324139131/1169941928041783337/1169941928041783337