Contributed scripts/pkgs to use Workrave in taskbar apps, such as Waybar, SFWBary, Yambar, Swaybar, and so on.

This is basically a flake to Nixify installation of the Python scripts seen here: https://github.com/rcaelers/workrave/tree/main/contrib/waybar-yambar-poss-other-applets

However, rather than use workrave_break_info.py as both a script and a module, the workrave_break_info module from PyPi is used, and workrave-break-info is used wherever workrave_break_info.py would be used as a script.

Since Workrave is under GPL-3.0, the scripts and modules here are also under GPL-3.0. The Nix code, though, is simply under the MIT license.