feat!: introduce MsgOptIn and MsgOptOut (#1620)

* init commit

* cleaning up

* changed cons to val address

* Revert "changed cons to val address"

This reverts commit a32e882.

* Update x/ccv/provider/keeper/keeper.go

Co-authored-by: Simon Noetzlin <[email protected]>

* took into account comments

* added key assignment

* add contraint such that opt out only works if the chain is running

---------

Co-authored-by: insumity <[email protected]>
Co-authored-by: Simon Noetzlin <[email protected]>

proto/interchain_security/ccv/provider/v1/tx.proto

@@ -109,4 +109,4 @@ message MsgSetConsumerCommissionRate {
 }
 
 
-message MsgSetConsumerCommissionRateResponse {}
+message MsgSetConsumerCommissionRateResponse {}