Rename Ryujinx.Core to Ryujinx.HLE and add a separate project for a future LLE implementation

Ryujinx.HLE/OsHle/Services/Friend/IFriendService.cs

@@ -0,0 +1,20 @@
+using Ryujinx.HLE.OsHle.Ipc;
+using System.Collections.Generic;
+
+namespace Ryujinx.HLE.OsHle.Services.Friend
+{
+    class IFriendService : IpcService
+    {
+        private Dictionary<int, ServiceProcessRequest> m_Commands;
+
+        public override IReadOnlyDictionary<int, ServiceProcessRequest> Commands => m_Commands;
+
+        public IFriendService()
+        {
+            m_Commands = new Dictionary<int, ServiceProcessRequest>()
+            {
+                //...
+            };
+        }
+    }
+}