Add modifying of VAST for video bids and add validation

src/main/java/org/prebid/server/auction/model/BidInfo.java

@@ -0,0 +1,26 @@
+package org.prebid.server.auction.model;
+
+import com.iab.openrtb.request.Imp;
+import com.iab.openrtb.response.Bid;
+import lombok.Builder;
+import lombok.Value;
+import org.prebid.server.proto.openrtb.ext.response.BidType;
+
+@Builder(toBuilder = true)
+@Value
+public class BidInfo {
+
+    String generatedBidId;
+
+    Bid bid;
+
+    Imp correspondingImp;
+
+    String bidder;
+
+    BidType bidType;
+
+    public String getBidId() {
+        return generatedBidId != null ? generatedBidId : bid.getId();
+    }
+}