[GOG] Cloud Saves support

[imLinguin]

This PR is also some sort of refactor of cloud saves.
Notes:

• Save paths now use environment variables, thus allowing for better compatibility in case wine changes things there
• runWineCommand will default to runinprefix verb by default
• Obtaining save path is based on winepath command
• Syncing saves is using gogdl

Use the following Checklist if you have changed something on the Backend or Frontend:

• Tested the feature and it's working on a current and clean install.
• Tested the main App features and they are still working on a current and clean install. (Login, Install, Play, Uninstall, Move games, etc.)
• Created / Updated Tests (If necessary)
• Created / Updated documentation (If necessary)

[imLinguin]

I believe we are now in testing phase, there are some exceptions in case of finding games that support Cloud Saves feature. Case I know for sure is Cyberpunk 2077. It's a critical inaccuracy, before we merge this we need to find another way of checking if feature is supported.

[flavioislima]

Looks good. Left just a few comments.
would be also nice to add the text with a warning that this feature is in Beta (for both epic and gog) and to backup the saves before using it. ⚔️