Support for multiple providers in a single order.

[vbabuEM]

Moving this from an issue to this forum. Here are the messages so far on the issue

Is your feature request related to a problem? Please describe.
Currently the Order object in the Beckn spec has a single provider object. This limits the items that can be added to the order to a single Provider(seller). This is restrictive for multi-seller setups (e.g. setups like amazon, etsy etc).

Describe the solution you'd like
Order object, just like the catalog object should support multiple providers.

Describe alternatives you've considered
BAP will currently have to split an order into multiple orders even if it is the same BPP.

Additional context
Search operation supports searching multiple BPPs and multiple providers within single BPP. Once the order is created, restricting the order to be to a single BPP seems reasonable. Restricting order to a single provider(seller) seems excessively restrictive.

[vbabuEM]

Comment From @venkatramanm on the issue before it was moved here.

Every seller-location needs an order for fulfillment and communication back and forth would be needed for the same.

Some one has to split the orders by provider location.

Bap any way needs to split by bpps.

So the logic to split by location is a simple extension on the bap side.

Communication of exceptions would become complex if the seller order is hidden from the bap.?

Even if multiple sellers were possible in a single order., there will be multiple deliveries and communication / refunds /... would get more complicated.

Hence this simplification. Which manages all the usecases with a simpler api.

[vbabuEM]

Link to the issue before it was closed and moved here
#402