Sam Heughan writes in his new memoir, “Waypoints: My Scottish Journey,” that he felt “betrayed” by the “Outlander” creative team after he was pushed into filming a full frontal nudity scene during the end of the Starz drama series’ first season (via Insider). Heughan, who has been the co-lead of “Outlander” since its 2014 debut, was contractually required to film …