It must be nice to have “Hamilton” on your side.With “Blindspotting,” the successful transition from stage to screen for Daveed Diggs, the Oakland, Calif., native, rap artist and Brown University grad who won a 2016 Tony Award as Best Featured Actor in a Musical for his performance as the Marquis de Lafayette and Thomas Jefferson in the Broadway production of “Hamilton,” has been sealed.Diggs co-wrote and starred in the Oakland-based film with his high school friend, Rafael Casal (&ldquo …