Todd Spangler NY Digital EditorTwin music duo Tegan and Sara’s best-selling memoir “High School” will be adapted as an original series for Amazon’s IMDb TV free, ad-supported streaming service.The show, announced as part of Amazon’s first-ever NewFronts presentation Monday, will be executive produced by identical twins Tegan and Sara and writer-director-actor Clea DuVall.“High School” is a coming-of-age scripted series described as “a transcendent story of first loves and first songs.” The