Enable query from provider to return correct genesis state for sovereign to consumer changeover chains

[shaspitz]

As of #757, where all changes only affect consumers, a sovereign to consumer changeover chain will have to query the provider for a genesis state, manually change that genesis JSON before it is used on consumer, then the consumer reads that file. See this code.

A future improvement to ICS could introduce a change that affects the provider (MAJOR version bump), s.t there's a provider query returning a properly crafted sovereign to consumer genesis state with more devops automation

[mpoke]

Closing in favor of #894