GRAND FORKS — Summer Performing Arts is returning next month with two musical productions for the community to enjoy. Incoming junior and senior students are spending the first several weeks of their summer preparing for “Frozen,” which is based on the hit 2013 Disney animated film. Meanwhile, freshman and sophomores are gearing up for their production of “Seussical,” which features a plot based around “Horton Hears a Who,” but contains a number…