Implemented Wallpaper Selector and Matugen's Wallpaper based auto-theming. (#73)

* Implement matugen - WIP

* Added matugen

* Add types and cleanup code

* Matugen implementation updates and added more options such as scheme and contrast.

* Code cleanup and matugen settings renamed for clarity.

* Makon maroon a primary matugen color.

* Updates to handle variations of matugen colors

* Finalizing matugen and wrapping up variations.

* Minor styling updates of the settings dialog.

* Do a swww dependency check.

* Dependency logic update

* Switch shouldn't double trigger notifications now when checking dependency.

* Logic was inverted

* Add matugen to dependency checker.

* Fixed dependency checking conditional

* Update dependency list in readme and check for matugen before doing matugen operations

* Styling fixes

* OSD Fix

* Remove unused code from wallpaper service.

* Color fixes for matugen.

* Nix updates for new dependencies

* Change default wallpaper to empty.

* Added custom notification service for startup, cleaned up code and updated readme.

scss/style/bar/workspace.scss

@@ -42,7 +42,7 @@
     }
 
     &.underline {
-      border-bottom: 0.1em solid $pink;
+      border-bottom: 0.1em solid $bar-buttons-workspaces-numbered_active_text_color;
     }
 
     &.highlight {