feat(abcip): thread nested-struct template id so nested UDT members are addressable (#6)

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbCip/AbCipTemplateCache.cs

@@ -54,8 +54,16 @@ public sealed record AbCipUdtShape(
     IReadOnlyList<AbCipUdtMember> Members);
 
 /// <summary>One member of a Logix UDT.</summary>
+/// <param name="Name">Member name as reported by the Template Object.</param>
+/// <param name="Offset">Byte offset of the member from the struct start.</param>
+/// <param name="DataType">Decoded member data type (<see cref="AbCipDataType.Structure"/> for a nested UDT).</param>
+/// <param name="ArrayLength">Element count (1 for a scalar member).</param>
+/// <param name="NestedTemplateId">For a nested-struct member, the nested UDT's CIP template instance id
+///     (low 12 bits of the member info, same encoding as the Symbol Object) so the nested shape can be
+///     fetched via <see cref="AbCipDriver.FetchUdtShapeAsync"/>; <c>null</c> for a scalar member.</param>
 public sealed record AbCipUdtMember(
     string Name,
     int Offset,
     AbCipDataType DataType,
-    int ArrayLength);
+    int ArrayLength,
+    uint? NestedTemplateId = null);