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/menus/audiomenu.scss

@@ -62,6 +62,11 @@
   }
 }
 
+.menu-active-percentage.playback,
+.menu-active-percentage.input {
+  color: if($bar-menus-monochrome, $bar-menus-text, $bar-menus-menu-volume-text);
+}
+
 .menu-active-button {
 
   .menu-active-icon.playback,
@@ -120,7 +125,7 @@
 
     .menu-button-name.playback,
     .menu-button-name.input {
-      color: if($bar-menus-monochrome, $bar-menus-icons-active, $bar-menus-menu-volume-icons-active);
+      color: if($bar-menus-monochrome, $bar-menus-listitems-active, $bar-menus-menu-volume-listitems-active);
     }
   }
 }
@@ -165,4 +170,4 @@
 
 .menu-items-section.playback {
   border-radius: 0em;
-}
+}