* downgrade to ibc v7 for ibc tests
* add conformance test (does not pass consistently)
* limit number of nodes for more consistent passing
* update to upstream v7 branch of interchaintest
also, remove unnecessary go.mod replace statements
* better names for int pointers
* setup interchaintest IBC test
* e2e test of packet forwarding middleware
* rename interchain -> e2e-ibc & add make cmd
* add CI step that runs e2e-ibc tests
* use current branch for docker image in e2e-ibc