Wire DCL to Instance Actors for OPC UA tag value flow

- Add TagValueUpdate/ConnectionQualityChanged handlers to InstanceActor
- InstanceActor subscribes to DCL on PreStart based on DataSourceReference
- DeploymentManagerActor creates DCL connections on deploy and passes DCL ref
- AkkaHostedService creates DCL Manager Actor for tag subscriptions
- Move CreateConnectionCommand to Commons for cross-project access
- Add ConnectionConfig to FlattenedConfiguration for deployment packaging

src/ScadaLink.DataConnectionLayer/Actors/DataConnectionManagerActor.cs

@@ -123,14 +123,6 @@ public class DataConnectionManagerActor : ReceiveActor
     }
 }
 
-/// <summary>
-/// Command to create a new data connection actor for a specific protocol.
-/// </summary>
-public record CreateConnectionCommand(
-    string ConnectionName,
-    string ProtocolType,
-    IDictionary<string, string> ConnectionDetails);
-
 /// <summary>
 /// Command to remove a data connection actor.
 /// </summary>