[Feature Request] Add support for XDG Base Directory for GNU/Linux build

Describe the feature request

On GNU/Linux there is XDG Base Directory specification and convention for systemd based distros. It have env XDG_CONFIG_HOME which by default points to $HOME/.config and it's analogous to /etc. On such disros it's an expected behavior to seek a config in $XDG_CONFIG_HOME, /etc and ./.

If you would like to make such a behavior for all supported OS, you can use %AppData% on windows and ~/Library/Preferences for macos.

Describe alternatives you've considered

No response

Affected area

• Docs
• Installation
• Performance and Scalability
• Security
• User Experience
• Test and Release
• Developer Infrastructure
• Client Plugin
• Server Plugin
• Extensions
• Others