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/Bcat/ServiceCreator/IDeliveryCacheStorageService.cs

@@ -0,0 +1,47 @@
+using Ryujinx.HLE.HOS.Services.Arp;
+using System;
+using System.Text;
+
+namespace Ryujinx.HLE.HOS.Services.Bcat.ServiceCreator
+{
+    class IDeliveryCacheStorageService : IpcService
+    {
+        private const int DeliveryCacheDirectoriesLimit    = 100;
+        private const int DeliveryCacheDirectoryNameLength = 32;
+
+        private string[] _deliveryCacheDirectories = new string[0];
+
+        public IDeliveryCacheStorageService(ServiceCtx context, ApplicationLaunchProperty applicationLaunchProperty)
+        {
+            // TODO: Read directories.meta file from the save data (loaded in IServiceCreator) in _deliveryCacheDirectories.
+        }
+
+        [Command(10)]
+        // EnumerateDeliveryCacheDirectory() -> (u32, buffer<nn::bcat::DirectoryName, 6>)
+        public ResultCode EnumerateDeliveryCacheDirectory(ServiceCtx context)
+        {
+            long outputPosition = context.Request.ReceiveBuff[0].Position;
+            long outputSize     = context.Request.ReceiveBuff[0].Size;
+
+            for (int index = 0; index < _deliveryCacheDirectories.Length; index++)
+            {
+                if (index == DeliveryCacheDirectoriesLimit - 1)
+                {
+                    break;
+                }
+
+                byte[] directoryNameBuffer = Encoding.ASCII.GetBytes(_deliveryCacheDirectories[index]);
+
+                Array.Resize(ref directoryNameBuffer, DeliveryCacheDirectoryNameLength);
+
+                directoryNameBuffer[DeliveryCacheDirectoryNameLength - 1] = 0x00;
+                
+                context.Memory.WriteBytes(outputPosition + index * DeliveryCacheDirectoryNameLength, directoryNameBuffer);
+            }
+
+            context.ResponseData.Write(_deliveryCacheDirectories.Length);
+
+            return ResultCode.Success;
+        }
+    }
+}