causal delivery of deltas, #22188

* keep track of delta interval versions and skip deltas
  that are not consequtive, i.e. when some delta message was lost
* send the delta versions in the full state gossip to sync up the
  expected versions after dropped deltas
* implementation of deltas for ORSet
* refactoring of the delta types to allow for different type for the
  delta and the full state
* extensive tests
* mima filter
* performance optimizations
* simple pruning of deltas
* Java API
* update documentation
* KeyId type alias
* Use InternalApi annotation

akka-distributed-data/src/multi-jvm/scala/akka/cluster/ddata/ReplicatorSpec.scala

@@ -22,6 +22,7 @@ object ReplicatorSpec extends MultiNodeConfig {
     akka.loglevel = INFO
     akka.actor.provider = "cluster"
     akka.log-dead-letters-during-shutdown = off
+    #akka.cluster.distributed-data.delta-crdt.enabled = off
     """))
 
   testTransport(on = true)