You’re invited to party. No need to RSVP, just show up at Goodman’s Owen Theater between now and April 28 to see “Lottery Day,” the last of seven plays by Ike Holter about the residents of the fictional community of Rightlynd, a recently gentrified neighborhood in Chicago’s “51st Ward.”Believe me, you’ll have a blast watching one of the finest ensemble casts in years, under the …