The ability to run non-steam game on a certain prefix using WINE

[Ahmed-E-86]

Your system information

• Steam client version (build number or date):
• Distribution (e.g. Ubuntu): Kubuntu 20.04.1
• Opted into Steam client beta?: Yes
• Have you checked for system updates?: Yes

When I add non-steam game Proton make a prefix for this game inside ~/.steam/steam/steamapps/compatdata/

I already have WINE prefixes for these non-steam games including save games, and I just want to run these games on the WINE prefixes I created before, and I want to open these games using WINE not Proton, because Proton creates a folder called steamuser, not the folder that WINE uses.

I can open these games directly using WINE without having to use Steam, but I want these games to be added to Steam, because I want to stream these games using Steam Link.

Could you please add the ability to run non-steam games using WINE and choosing the location of WINE prefix?

[kisak-valve]

Partial duplicate of #5674.