Certificate/wireless plugins; major refactoring

Migrate much of BI to Services.
Added Wireless Profile Provider plugin feature.
Added Certificate Authority Provider plugin feature.
Modified Certificate Provider plugin feature.
Database migration v17, for Device Profiles.
Enrolment Client Updated to support CA Certificates, Wireless Profiles
and Hardware Info.
New Client Enrolment Protocol to support new features.
Plugin Manifest Generator added to main solution.
Improved AD search performance.

Disco.Services/Plugins/Plugins.cs

@@ -1,7 +1,6 @@
 using Disco.Data.Repository;
 using Disco.Models.Services.Interop.DiscoServices;
 using Disco.Services.Interop.DiscoServices;
-using Newtonsoft.Json;
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -187,15 +186,22 @@ namespace Disco.Services.Plugins
         }
         public static bool TryGetPluginFeature(string PluginFeatureId, Type CategoryType, out PluginFeatureManifest PluginFeatureManifest)
         {
-            PluginFeatureManifest = null;
-
             if (_PluginManifests == null)
+            {
+                PluginFeatureManifest = null;
                 return false;
+            }
 
-            var featureManifest = _PluginManifests.Values.SelectMany(pm => pm.Features).Where(fm => fm.Id == PluginFeatureId).FirstOrDefault();
+            var featureManifest = _PluginManifests.Values
+                .SelectMany(pm => pm.Features)
+                .Where(fm => fm.Id == PluginFeatureId)
+                .FirstOrDefault();
 
             if (featureManifest == null)
+            {
+                PluginFeatureManifest = null;
                 return false;
+            }
 
             if (CategoryType == null)
             {
@@ -210,7 +216,10 @@ namespace Disco.Services.Plugins
                     return true;
                 }
                 else
+                {
+                    PluginFeatureManifest = null;
                     return false;
+                }
             }
         }
         public static PluginFeatureManifest GetPluginFeature(string PluginFeatureId)