provide user a mechanism to choose a OKH

[tz-earl]

No description provided.

[devhawk]

Changed title from Choose OKH to choose Product because a given product may have multiple OKH designed, each of which will have potentially multiple supply chains. Users may want to pick a specific design for their own reasons, but from our perspective, the driving issue is availability of supply chains. In other words, if a given design has no possible supply chains to deliver it, the user won't want to choose that design.

[RobertLRead]

Can we reach S3 from client-side (browser) javascript? This is a high priority in terms of our next architectural steps.