renamed DynamicDocumentList to DynamicPublishedContentList

simplified some of the DynamicPublishedContent methods to accept Func<IPublishedContent> instead of Func<DynamicPublishedContent>, made the IsHelper method private as this shouldn't be exposed.
renamed other objects starting with DynamicDocument to DynamicPublishedContent

src/Umbraco.Core/Dynamics/IDynamicPublishedContentDataSource.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+
+namespace Umbraco.Core.Dynamics
+{
+	/// <summary>
+	/// This exists only because we want Dynamics in the Core project but DynamicNode has references to ContentType to run some queries
+	/// and currently the business logic part of Umbraco is still in the legacy project and we don't want to move that to the core so in the
+	/// meantime until the new APIs are made, we need to have this data source in place with a resolver which is set in the web project.
+	/// </summary>
+	internal interface IDynamicPublishedContentDataSource
+	{
+		Guid GetDataType(string docTypeAlias, string propertyAlias);
+
+	}
+}