* Varia: add tertiary styles conditionally
Varia is a parent theme and the tertiary styles are not defined.
It effects all of its child themes such as stow.
* create styles for tertiary blocks
* add the styles conditionally so that child themes that has tertiary will get the classes
* add tertiary color and background styling
* Stow
* Hever
* Rockfield
* Stratford
* rebuild child themes with Varia changes
