dank-material-shell: add module

[artur-sannikov]

Description

Adds a module for DankMaterialShell, a bar for Wayland window managers.

They already provide a module for Home Manager in their repo, so I stitched together what they already had there and tested that it works with Home Manager.

One thing I did not manage to do is the automatic reloading of the systemd unit when the config changes. NixOS provides this functionality with systemd.user.services..reloadIfChanged, but it does not seem to work with Home Manager. Actually, their module also does not reload the unit.

Also, it's a "program", not a service, even though some other shells like hyprshell are services. I just followed what they already had in the repo, and wanted to maintain compatibility with stylix, which assumes programs.dank-material-shell.

Test the module by setting the flake input of home-manager to github:artur-sannikov/home-manager/add-module-dms, remove inputs.nixpkgs.follows = "nixpkgs", and then use the example-config.nix from the tests of this PR.

I'm on NixOS, using home-manager as a module, so I would appreciate tests from those who do not use flakes/use standalone home-manager.

Checklist

• Change is backwards compatible.

• Code formatted with nix fmt or
  nix-shell -A dev --run treefmt.

• Code tested through nix build .#test-all
  or a targeted nix run .#tests -- <pattern>.

• 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.
  • Generate a news entry. See News
  • Basic tests added. See Tests

• If this PR adds an exciting new feature or contains a breaking change.

  • Generate a news entry. See News