FLANDREAU, S.D. — Two consultants who worked with a Native American tribe on its plans to open the nation’s first marijuana resort in rural South Dakota have been charged with drug offenses, the state’s attorney general announced Wednesday. The charges come eight months after the Flandreau Santee Sioux destroyed their crop amid fears of a federal raid, abandoning an ambitious scheme to develop “an adult playground” that they estimated could net as much as $2 million a month in profits.