refactor(opcuaserver): rename Phase7* address-space pipeline to AddressSpace*

The OPC UA address-space build pipeline was named after a v2-roadmap
milestone number rather than its domain. Rename the family to describe
what it does (build/diff/apply the OPC UA address space):

  Phase7Composer          -> AddressSpaceComposer
  Phase7CompositionResult -> AddressSpaceComposition
  Phase7Planner           -> AddressSpacePlanner
  Phase7Plan              -> AddressSpacePlan
  Phase7Applier           -> AddressSpaceApplier
  Phase7ApplyOutcome      -> AddressSpaceApplyOutcome

The 9 Phase7*Tests suites follow suit; Phase7ScriptingEntitiesTests ->
ScriptingEntitiesTests (it tests the scripting migration, not the
pipeline). Log-message prefixes move to the new class names.

Pure mechanical rename, no behavioral change. EF migration classes/IDs
(AddPhase7ScriptingTables, ExtendComputeGenerationDiffWithPhase7) are
immutable and left untouched, as are historical design docs.

Build clean; OpcUaServer 261/261, Runtime 272/272, ScriptingEntities
12/12 green.

src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Drivers/DriverHostActor.cs

@@ -939,7 +939,7 @@ public sealed class DriverHostActor : ReceiveActor, IWithTimers
             return;
         }
 
-        Phase7CompositionResult composition;
+        AddressSpaceComposition composition;
         try
         {
             composition = DeploymentArtifact.ParseComposition(blob, _localNode.Value);