Motivation for this change

iwd is a new wireless daemon mainly developed by Intel.
The module added is pretty basic and not very practical at the moment due missing external agents (for wifi password callbacks). However it might serve well as a technical preview.

Usage:

# /etc/nixos/configuration.nix
network.wireless.enable = false; # if it was enabled before
network.wireless.iwd.enable = true;

$ iwctl
[iwd]# help
....
[iwd]# device list
                                    Devices
--------------------------------------------------------------------------------
  Name                Address             State          Adapter   
--------------------------------------------------------------------------------
  wlp3s0              34:02:86:1a:7b:47   disconnected   phy0

Things done

• Tested using sandboxing
  (nix.useSandbox on NixOS,
  or option build-use-sandbox in nix.conf
  on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • Linux
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Fits CONTRIBUTING.md.