The className prop was sometimes set onto the nested element and
sometimes on the container element, which was not consistent. Now
we always set the className onto the upmost element.
Since the addition of tertiary-text variant, the original tertiary
variant has seen its background color changing from transparent to
greyscale-100, the change has impacted lots of components making
them look odd. So that's why I updated most of old tertiary to
tertiary-text.
Fixes#223
Replaced deprecated '@import' with '@use' to align with best practices.
Refactored stylesheet to behave as a partial, enhancing SASS compilation
efficiency.
The stories do not need CunninghamProvider anymore since it is
handled by the configuration for the themes support. Some stories
were also using wrong colors that didn't handle multiple themes.
Some components were using wrong design tokens and this was noticed
only when changing themes, like using hard-coded "white" instead of
"greyscale-000".
