Adds MediaFactory implementation U4-985

Adds MediaRepository implementation U4-957
Refactoring ContentType and MediaType to have parent id as constructor dependency.
Refactoring PropertyFactory to work for both Content and Media.
Adding Version property to Media.

src/Umbraco.Core/Models/IContent.cs

@@ -23,11 +23,6 @@ namespace Umbraco.Core.Models
         /// </summary>
         //string Language { get; set; }
 
-        /// <summary>
-        /// Gets the Guid Id of the Content's Version
-        /// </summary>
-        Guid Version { get; }
-
         /// <summary>
         /// Gets or Sets the date the Content should be released and thus be published
         /// </summary>