Add less patterns from cfgov-refresh

Adds:
- figure img enhancements
- .superheader line height reduction
- .u-small-text small text utility
- hide/show on mobile utility classes
- percentage width utility classes
- .list with brand-color bullets
I'd rename this to just "Figure" and pull the figure margin-left/right down in here too. I'd leave the figure margin top/bottom in that big vertical margin list.