feat: Resolve all deprecation warnings for sass

- Replace @import with @use and @forward
- Only color function is used in _basic.scss for now
- Change _all.scss to _index.scss
- Modules use direct dependencies
- Move @include from _config.scss to _common.scss, this was a long term mistake
- Remove $color_list
- Change basic_color()

_hippie.scss

@@ -21,13 +21,13 @@
     - Maintenance
 *
  */
-@import "basic";
+@forward "basic";
 
 // Additional Modules and variables
 // in dependency to other basic styles
 // -----------------------------------------------------------------------------
-@import "modules/io/io_module";
-@import "modules/navigation/nav_module";
-@import "modules/editor/editor_module";
-@import "modules/explanation/explanation_module";
-@import "modules/print/print_module";
+@forward "modules/io/io_module";
+@forward "modules/navigation/nav_module";
+@forward "modules/editor/editor_module";
+@forward "modules/explanation/explanation_module";
+@forward "modules/print/print_module";