Refactoring HOS folder structure (#771)

* Refactoring HOS folder structure

Refactoring HOS folder structure:

- Added some subfolders when needed (Following structure decided in private).
- Added some `Types` folders when needed.
- Little cleanup here and there.
- Add services placeholders for every HOS services (close #766 and #753).

* Remove Types namespaces

Ryujinx.HLE/HOS/Services/Fs/FileSystemProxy/IDirectory.cs

@@ -0,0 +1,84 @@
+using LibHac;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Ryujinx.HLE.HOS.Services.Fs.FileSystemProxy
+{
+    class IDirectory : IpcService
+    {
+        private const int DirectoryEntrySize = 0x310;
+
+        private IEnumerator<LibHac.Fs.DirectoryEntry> _enumerator;
+
+        private LibHac.Fs.IDirectory _baseDirectory;
+
+        public IDirectory(LibHac.Fs.IDirectory directory)
+        {
+            _baseDirectory = directory;
+            _enumerator    = directory.Read().GetEnumerator();
+        }
+
+        [Command(0)]
+        // Read() -> (u64 count, buffer<nn::fssrv::sf::IDirectoryEntry, 6, 0> entries)
+        public ResultCode Read(ServiceCtx context)
+        {
+            long bufferPosition = context.Request.ReceiveBuff[0].Position;
+            long bufferLen      = context.Request.ReceiveBuff[0].Size;
+
+            int maxReadCount = (int)(bufferLen / DirectoryEntrySize);
+            int readCount    = 0;
+
+            try
+            {
+                while (readCount < maxReadCount && _enumerator.MoveNext())
+                {
+                    long position = bufferPosition + readCount * DirectoryEntrySize;
+
+                    WriteDirectoryEntry(context, position, _enumerator.Current);
+
+                    readCount++;
+                }
+            }
+            catch (HorizonResultException ex)
+            {
+                return (ResultCode)ex.ResultValue.Value;
+            }
+
+            context.ResponseData.Write((long)readCount);
+
+            return ResultCode.Success;
+        }
+
+        private void WriteDirectoryEntry(ServiceCtx context, long position, LibHac.Fs.DirectoryEntry entry)
+        {
+            for (int offset = 0; offset < 0x300; offset += 8)
+            {
+                context.Memory.WriteInt64(position + offset, 0);
+            }
+
+            byte[] nameBuffer = Encoding.UTF8.GetBytes(entry.Name);
+
+            context.Memory.WriteBytes(position, nameBuffer);
+
+            context.Memory.WriteInt32(position + 0x300, (int)entry.Attributes);
+            context.Memory.WriteInt32(position + 0x304, (byte)entry.Type);
+            context.Memory.WriteInt64(position + 0x308, entry.Size);
+        }
+
+        [Command(1)]
+        // GetEntryCount() -> u64
+        public ResultCode GetEntryCount(ServiceCtx context)
+        {
+            try
+            {
+                context.ResponseData.Write((long)_baseDirectory.GetEntryCount());
+            }
+            catch (HorizonResultException ex)
+            {
+                return (ResultCode)ex.ResultValue.Value;
+            }
+
+            return ResultCode.Success;
+        }
+    }
+}