The identifier for the vendor that may sell this item.
Mapped to DestinyVendorDefinition in the manifest.
The Vendor sale item indexes that represent the sale information for this item. The same vendor may sell an item in multiple "ways", hence why this is a list. ( for instance, a weapon may be "sold" as a reward in a quest, for Glimmer, and for Masterwork Cores: each of those ways would be represented by a different vendor sale item with a different index)
Represents that a vendor could sell this item, and provides a quick link to that vendor and sale item.
Note that we do not and cannot make a guarantee that the vendor will ever * actually* sell this item, only that the Vendor has a definition that indicates it could be sold.
Note also that a vendor may sell the same item in multiple "ways", which means there may be multiple vendorItemIndexes for a single Vendor hash.