rememberingEntities with ddata mode, #22154

* one Replicator per configured role
* log LMDB directory at startup
* clarify the imporantce of the LMDB directory
* use more than one key to support many entities

akka-cluster-sharding/src/multi-jvm/scala/akka/cluster/sharding/ClusterShardingGetStatsSpec.scala

@@ -56,6 +56,10 @@ object ClusterShardingGetStatsSpecConfig extends MultiNodeConfig {
       updating-state-timeout = 2s
       waiting-for-state-timeout = 2s
     }
+    akka.cluster.sharding.distributed-data.durable.lmdb {
+      dir = target/ClusterShardingGetStatsSpec/sharding-ddata
+      map-size = 10 MiB
+    }
     akka.actor.warn-about-java-serializer-usage=false
     """))