feat: make AsyncDataTable and AsyncDataSet wrapping constructors and Inner properties public

Enables user code to wrap existing DataTable/DataSet instances:
  new AsyncDataTable(existingDataTable)
  new AsyncDataSet(existingDataSet)

Also exposes InnerDataTable and InnerDataSet for interop scenarios.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: MarcelRoozekrans

src/System.Data.Async.DataSet/AsyncDataSet.cs

@@ -9,9 +9,9 @@ public class AsyncDataSet : IDisposable
 
     public AsyncDataSet() => _inner = new System.Data.DataSet();
     public AsyncDataSet(string dataSetName) => _inner = new System.Data.DataSet(dataSetName);
-    internal AsyncDataSet(System.Data.DataSet inner) => _inner = inner ?? throw new ArgumentNullException(nameof(inner));
+    public AsyncDataSet(System.Data.DataSet inner) => _inner = inner ?? throw new ArgumentNullException(nameof(inner));
 
-    internal System.Data.DataSet InnerDataSet => _inner;
+    public System.Data.DataSet InnerDataSet => _inner;
 
     // Properties
     public string DataSetName { get => _inner.DataSetName; set => _inner.DataSetName = value; }

src/System.Data.Async.DataSet/AsyncDataTable.cs

@@ -11,9 +11,9 @@ public class AsyncDataTable : IDisposable
     public AsyncDataTable() => _inner = new DataTable();
     public AsyncDataTable(string tableName) => _inner = new DataTable(tableName);
     public AsyncDataTable(string tableName, string tableNamespace) => _inner = new DataTable(tableName, tableNamespace);
-    internal AsyncDataTable(DataTable inner) => _inner = inner ?? throw new ArgumentNullException(nameof(inner));
+    public AsyncDataTable(DataTable inner) => _inner = inner ?? throw new ArgumentNullException(nameof(inner));
 
-    internal DataTable InnerDataTable => _inner;
+    public DataTable InnerDataTable => _inner;
 
     // Properties - all delegate to _inner
     public string TableName { get => _inner.TableName; set => _inner.TableName = value; }