IndyCar promoters have been huddling with state agencies this week to hash out what they need to put on a Grand Prix-style road race in the Seaport next year, according to Gov. Charlie Baker.The confab -- which Baker said has ranged over multiple meetings and is still ongoing -- came after various state and quasi-public agencies held individual sessions with race promoters, though they remained far from reaching any deals needed to put on the September 2016 race.