add polkit modules

[bobvanderlinden]

Description

Supersedes #5619
Resolves #3739

This adds polkit agent services for hyprland, gnome and lxqt. I have had the one from lxqt in my own configuration for a while and served me well, but recently wanted to check out other polkits and eventually switched to gnome's one.
I thought I'd add these to home-manager as well this time.

I was contemplating adding security.polkit.agent = "gnome" or "hyprland" or "lxqt", but since there was no security directory I wasn't sure that was the right call for now and could be a future step.

All 3 of these tools do not have configuration(-files).

Checklist

• Change is backwards compatible.

• Code formatted with ./format.

• Code tested through nix-shell --pure tests -A run.all
  or nix build --reference-lock-file flake.lock ./tests#test-all using Flakes.

• Test cases updated/added. See example.

• Commit messages are formatted like

  {component}: {description}
  
  {long description}
  

  See CONTRIBUTING for more information and recent commit messages for examples.

• If this PR adds a new module

  • Added myself as module maintainer. See example.

Maintainer CC