Steam Cloud file read/write support

[carloslbello]

Is your feature request related to a problem? Please describe.

I'm trying to create a script that synchronizes game save files across different services, such as Steam and Apple App Store.

Describe the solution you'd like

Methods for accessing Steam Cloud files for the logged in user, including, by app ID, enumerating existing files' names and when they were last modified, reading, writing, and deleting files.

Describe alternatives you've considered

It seems like I could access Steam Cloud programmatically using SteamKit2, however I don't have experience with C# and the other cloud services I am exploring support for do not have C# client libraries available, while many have Node client libraries.

Additional context

None