freecad: fix missing app icon and name when running under Wayland

[lightbulbjim]

Motivation for this change

Fixes the problem where the app icon would not show under Gnome/Wayland.

Wayland needs to know the name of the .desktop file to show a dock icon and application name.

See: https://community.kde.org/Guidelines_and_HOWTOs/Wayland_Porting_Notes#Application_Icon

Tested on Gnome/Wayland with the QT backend forced to Wayland, ie QT_QPA_PLATFORM=wayland. If QT_QPA_PLATFORM is unset (or is set to xcb) it uses XWayland.

The patch has been upstreamed and can be removed once a new release is available.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nix-review --run "nix-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

Notify maintainers

cc @viric @gebner

[worldofpeace]

@GrahamcOfBorg build freecad

[worldofpeace]

Thanks for fixing this like this for wayland ✨