Move kernel state out of the Horizon class (#1107)

* Move kernel state from Horizon to KernelContext

* Merge syscalls partial classes, split 32 and 64-bit variants

* Sort usings

Ryujinx.HLE/HOS/Services/IpcService.cs

@@ -168,7 +168,7 @@ namespace Ryujinx.HLE.HOS.Services
             }
             else
             {
-                KSession session = new KSession(context.Device.System);
+                KSession session = new KSession(context.Device.System.KernelContext);
 
                 session.ClientSession.Service = obj;