Pass ibc store for 09-localhost client verification

[damiannolan]

Summary

In 03-connection verify.go, the core IBC store should be passed to VerifyMembership and VerifyNonMembership when operating on the 09-localhost client.

A special case handling should be added to provide this functionality.
If the client type is localhost, then we should pass the core IBC store. Otherwise, the client prefixed store should be passed for other client types.

See reference from #2700.

func (k Keeper) getClientStateAndKVStore(ctx sdk.Context, clientID string) (exported.ClientState, sdk.KVStore, error) {
	clientStore := k.clientKeeper.ClientStore(ctx, clientID)

	clientState, found := k.clientKeeper.GetClientState(ctx, clientID)
	if !found {
		return nil, nil, sdkerrors.Wrap(clienttypes.ErrClientNotFound, clientID)
	}

	var store sdk.KVStore
	switch clientState.(type) {
	case *localhosttypes.ClientState:
		store = ctx.KVStore(k.storeKey)
	default:
		store = clientStore
	}

	if status := clientState.Status(ctx, store, k.cdc); status != exported.Active {
		return nil, nil, sdkerrors.Wrapf(clienttypes.ErrClientNotActive, "client (%s) status is %s", clientID, status)
	}

	return clientState, store, nil
}

The sample code above can be refactored. The status check can be removed and performed inside the verification handler.

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