* changed the environment variable `SteamAppPath` to `GseAppPath`
* allow loading `config.ini` from global settings path + merge it with the local one, and allow the local one to override the global one
* fixed the path returned by `get_user_appdata_path()` to include the path separator
* updated readmes
* new function in local storage to get list of folders at root level, given some path
* use last week epoch as the default time for mods dates (created, added, etc...)
* UGC: some params checks according to SDK docs for CreateQueryXXX() functions
* fixed some mistakes
* edits by Kola124 + other changes in the settings parser
* random ugc mod handle at object creation
* file size using std::filesystem + fix warnings + some print + arg validation