Jewelry trailblazer Sybil Yurman, cofounder of luxe brand David Yurman, once had a romance with singer James Taylor. Talk about a summer of love! Famed jeweler Sybil Yurman — cofounder of the luxe brand David Yurman — had a romance in the ’60s with famed “Fire and Rain” singer James Taylor. During a 92Y talk…