* fix(ssubscribe): properly resubscribe in case of shard failover
1) when RE failover happens, there is a disconnect
2) affected Client reconnects and tries to resubscribe all existing listeners
ISSUE #1: CROSSSLOT Error - client was doing ssubscribe ch1 ch2.. chN which, after the failover could result in CROSSSLOT ( naturally, becasuse now some slots could be owned by other shards )
FIX: send one ssubscribe command per channel instead of one ssubscribe for all channels
ISSUE #2: MOVED Error - some/all of the channels might be moved somewhere else
FIX: 1: Propagate the error to the Cluster. 2: Cluster rediscovers topology.
3: Cluster resubscribes all listeners of the failed client ( possibly some/all of those will end up in a different client after the rediscovery )
fixes: #2902
