OpenSea collection offers MVP

[ptrwtts]

Collection offers aren't nicely exposed, but you can get them by checking a single token, in this API:

https://api.opensea.io/api/v1/asset/0xbc4ca0eda7647a8ab7c2061c2e118a18a936f13d/3105/offers

You only need to check one token per collection, because it will apply to all.

As an initial test, let's pick one collection, or maybe a handful, and try to fetch the collection offers.