Add checks for WAI-ARIA techniques - WCAG_2.0

ARIA1, ARIA2, ARIA6, ARIA7, ARIA8, ARIA9, ARIA10, ARIA12,, ARIA13,
ARIA15, ARIA16
Add checks for WAI-ARIA techniques - WCAG_2.0

Check role attributes in decorative images - WCAG_2.0-F38.