Dynamically change dock/taskbar icon per game

[KKhanhH]

Setting the window icon on Windows and Mac will not change the icon on the dock, this needs a separate system call.

Linux has multiple DEs, so need to check if behavior is different per display servers and environments.
It's possible a desktop file is all that's needed on Linux.

• Windows
• Linux
• macOS

[Gunoshozo]

Btw, Intel Mac on MacOS 12.7.6 has dock icons just fine, IDK about apple silicon macs or later MacOS versions