+per #15424 Added PersistentView, deprecated View

A PersistentView works the same way as View did previously, except:

* it requires an `peristenceId` (no default is provided)
* messages given to `receive` are NOT wrapped in Persistent()

akka-streams not touched, will update them afterwards on different branch

Also solves #15436 by making persistentId in PersistentView abstract.

(cherry picked from commit dcafaf788236fe6d018388dd55d5bf9650ded696)

Conflicts:
	akka-docs/rst/java/lambda-persistence.rst
	akka-docs/rst/java/persistence.rst
	akka-docs/rst/scala/persistence.rst
	akka-persistence/src/main/scala/akka/persistence/Persistent.scala
	akka-persistence/src/main/scala/akka/persistence/View.scala

akka-samples/akka-sample-persistence-scala/src/main/scala/sample/persistence/ViewExample.scala

@@ -24,11 +24,10 @@ object ViewExample extends App {
     }
   }
 
-  class ExampleView extends View {
+  class ExampleView extends PersistentView {
     private var numReplicated = 0
 
     override def persistenceId: String = "persistentActor-5"
-
     override def viewId = "view-5"
 
     def receive = {
@@ -37,9 +36,11 @@ object ViewExample extends App {
       case SnapshotOffer(metadata, snapshot: Int) =>
         numReplicated = snapshot
         println(s"view received snapshot offer ${snapshot} (metadata = ${metadata})")
-      case Persistent(payload, _) =>
+      case payload if isPersistent =>
         numReplicated += 1
-        println(s"view received ${payload} (num replicated = ${numReplicated})")
+        println(s"view received persistent ${payload} (num replicated = ${numReplicated})")
+      case payload =>
+        println(s"view received not persitent ${payload}")
     }
 
   }