Bids: include array of items

[yolile]

When a tenderer submit a bid for an item this bid may include, besides the total amount of the bid, also the product specification of the item as the brand, model, etc. And it also may include the unit.name and unit.value of it.

For the product specification the local items attributes extension exists.

The proposal is to add the items array into the Bid object to indicate the specifications and units of the bidding items.

cc @jpmckinney

[jpmckinney]

To work through some more concrete examples:

• In a maintenance service contract for printers, a procuring entity might have lots for e.g. Canon printers, Brother printers, etc. These brand names would be part of a product description.
• In a contract for new printers, a procuring entity might have lots for printers in general (to avoid anti-competitive / illegal practices). These might not have any detailed product descriptions.
• In either case, however, it should be possible to indicate the unit prices related to the items in any lot, e.g. hourly rate for printer maintenance or purchasing price per printer.
• In either case, in the award, it is similarly useful to indicate this information, especially in cases where bids data isn't available. (When bids data is available, the award might just be repeating the information from the winning bid, but that is okay).

[yolile]

Extension drafted here

[cecicasco]

Hi! We gonna also use this local extension for Argentina's emergency publication, adding items and their price to the array of bids.

[duncandewhurst]

@jpmckinney any concerns about merging the bid_items_extension into the bids extension?

[jpmckinney]

@duncandewhurst Fine with me. Please review the field title/description when making the PR.

[yolile]

🎉