Ensures all resolvers are sealed. Changes CacheRefreshersResolver, DataTypesResolver, MacroFieldEditorsResolver, PackageActionsResolver, ActionsResolver

to all be lazy resolvers as they are not needed instantly on app startup (not needed by the front-end) This will
make app startup a lot quicker. Fixes ActionsResolver to not use the PluginManager to resolve the types when it
is instantiating them since these are passed in the ctor. Updates all unit tests to use lazy delegate for these resolvers
and they are all passing.

src/Umbraco.Core/ActionsResolver.cs

@@ -9,14 +9,14 @@ namespace Umbraco.Core
 	/// <summary>
 	/// A resolver to return all IAction objects
 	/// </summary>
-	internal sealed class ActionsResolver : ManyObjectsResolverBase<ActionsResolver, IAction>
+	internal sealed class ActionsResolver : LazyManyObjectsResolverBase<ActionsResolver, IAction>
 	{
 
 		/// <summary>
 		/// Constructor
 		/// </summary>
 		/// <param name="packageActions"></param>		
-		internal ActionsResolver(IEnumerable<Type> packageActions)
+		internal ActionsResolver(Func<IEnumerable<Type>> packageActions)
 			: base(packageActions)
 		{
 
@@ -34,9 +34,9 @@ namespace Umbraco.Core
 		}
 
 		protected override IEnumerable<IAction> CreateInstances()
-		{
+		{					
 			var actions = new List<IAction>();
-			var foundIActions = PluginManager.Current.ResolveActions();
+			var foundIActions = InstanceTypes;
 			foreach (var type in foundIActions)
 			{
 				IAction typeInstance;