Ownership Level Caching

[ptrwtts]

Right now, we cache the floor sell per token. But this does not work well for 1155 tokens, where multiple people can own the same token, and have different floor sells. It leads to inaccurate responses when fetching user tokens or the token's depth chart.

Instead, we should cache the floor sell per ownership, and use this data when calculating the above API reponses. Either we have a special case for 1155 tokens, or we use the ownership cache for 721 tokens too, where there should only be one ownership per token.

We probably also want the "on sale count", to avoid having to get this data from the orders table.