feat(table): scrolling variant, thead and tfoot colors, inverted colors

This PR adds a scrolling variant, which offers a scrollable table body having a fixed header and footer.
Just like for dropdown, i added height variants short, very short, long and very long respecting responsive layouts

I also fixed support for inverted colors for better readability and some specificity fixes to the disabled variant.
You can now also add colors to the thead or tfoot section of a table (using the new scrolling feature one has to add the color directly to thead or tfoot, while with normal tables one would have to add the colors to the tr tag as before (however, it was was not working inside thead/tfoot before this PR, not even with non inverted tables)

Author: lubber-de