DETROIT — Please, no jokes about sharks and lawyers — attorney Sarah Colegrove didn’t encounter any finny friends in her recent 21-mile swim across Lake St. Clair (the same distance across as the English Channel), although she learned afterward that Great Lakes freighters had come close from both directions. Lake St. Clair divides Detroit and Windsor, Ontario. “I’m glad I didn’t know that,” she said. Fulfilling a lifelong dream, 47-year-old Colegrove started her solo …