CSS variables for $table-color and $table-border-color are missing

Created by: Kopyov

Not sure if it's a bug, but leaving it here.

We have a set of CSS variables for .table class, but $table-color and $table-border-color are still using hardcoded HEX values, which means dark theme for instance still requires custom overrides of SASS or CSS values, while all other color changes can be made by overriding CSS vars.