Enable TreatWarningsAsErrors for MediaBrowser.Common and Emby.Photos

Adds `#pragma warning disable CS1591` to all files in
MediaBrowser.Common containing undocumented members.

MediaBrowser.Common/Providers/SubtitleConfigurationFactory.cs

@@ -1,3 +1,5 @@
+#pragma warning disable CS1591
+
 using System.Collections.Generic;
 using MediaBrowser.Common.Configuration;
 using MediaBrowser.Model.Providers;
@@ -6,6 +8,7 @@ namespace MediaBrowser.Common.Providers
 {
     public class SubtitleConfigurationFactory : IConfigurationFactory
     {
+        /// <inheritdoc />
         public IEnumerable<ConfigurationStore> GetConfigurations()
         {
             yield return new ConfigurationStore()