NGIN-13: The VAST invocation URL tag is fixed. Also the buy side workflow for Video was partially refactored and is ready for the VAST specific tag validation tasklets now. Also more params were added for the local demand tag processing for locally won auctions so that the buyer_id is identified by the loopback partner id plus the seat id which is the UserID of the demand dashboard user that owns the AdCampaignBanner that won.