Initiale hbmenu.nro support (#32)

* Initiale hbmenu.nro support

Implement missing SetScreenShotPermission object.
Implement missing IsCurrentProcessBeingDebugged in SVC.
Add a Extension variable to Executable.
Add basic support of hbmenu.nro.

* Homebrew.cs correction

Ryujinx.Core/Loaders/Executables/IExecutable.cs

@@ -2,6 +2,12 @@ using System.Collections.ObjectModel;
 
 namespace Ryujinx.Core.Loaders.Executables
 {
+    public enum Extensions
+    {
+        NRO,
+        NSO
+    }
+
     public interface IExecutable
     {
         ReadOnlyCollection<byte> Text { get; }
@@ -13,5 +19,7 @@ namespace Ryujinx.Core.Loaders.Executables
         int ROOffset   { get; }
         int DataOffset { get; }
         int BssSize    { get; }
+
+        Extensions Extension  { get; }
     }
 }