Minimize the amount that is pulled from upstream

[evan-forbes]

As we make more and more changes here, it stops making sense to merge changes from upstream in this fork. Instead of merging changes from upstream, which takes a long time to merge and is essentially impossible to review, we could instead only pull in the changes that matter for compatability with things that we care about.

This includes compatability with the sdk and IBC.

IBC likely works as is with a replace statement since there haven't been breaking changes to the proto files (that would mean IBC v6 would be unable to verify a v8)

The cosmos-sdk would require updates to interfaces, although we don't need to fully support those new methods unless we want to use them.