feat(commons): add DataType.List + ElementDataType companion for multi-value attributes

src/ZB.MOM.WW.ScadaBridge.Commons/Types/Enums/DataType.cs

@@ -8,5 +8,6 @@ public enum DataType
     Double,
     String,
     DateTime,
-    Binary
+    Binary,
+    List
 }

src/ZB.MOM.WW.ScadaBridge.Commons/Types/Flattening/FlattenedConfiguration.cs

@@ -66,6 +66,8 @@ public sealed record ResolvedAttribute
     public string? Value { get; init; }
     /// <summary>Gets the data type name.</summary>
     public string DataType { get; init; } = string.Empty;
+    /// <summary>For List attributes: the element scalar type name; null otherwise.</summary>
+    public string? ElementDataType { get; init; }
     /// <summary>Gets whether the attribute is locked.</summary>
     public bool IsLocked { get; init; }
     /// <summary>Gets the attribute description.</summary>