account: Implement IManagerForApplication calls and IAsyncContext (#1466)

* account: Implement IManagerForApplication calls and IAsyncContext

This implement:
- IManagerForApplication::EnsureIdTokenCacheAsync (accordingly to RE) but the Async task is stubbed.
- IAsyncContext interface (accordingly to RE).
- IManagerForApplication::LoadIdTokenCache (checked with RE, and stubbed).

I've tried some games but now they needs some `sfdnsres` calls, some other boots and crashes with other issues.
Maybe we should disable the connection somewhere to lets the game think we are offline. I have done many attempts, without success, but since the code is here now, it's better than nothing.

(I've cleaned up `using` of IGeneralService too)

Closes #629 and closes #630

* change AccountId

* Fix gdkchan's comments

* use CompletedTask

Ryujinx.HLE/HOS/Services/Account/Acc/IAsyncContext.cs

@@ -0,0 +1,79 @@
+using Ryujinx.HLE.HOS.Ipc;
+using Ryujinx.HLE.HOS.Kernel.Common;
+using Ryujinx.HLE.HOS.Services.Account.Acc.AsyncContext;
+using System;
+
+namespace Ryujinx.HLE.HOS.Services.Account.Acc
+{
+    class IAsyncContext : IpcService
+    {
+        AsyncExecution _asyncExecution;
+
+        public IAsyncContext(AsyncExecution asyncExecution)
+        {
+            _asyncExecution = asyncExecution;
+        }
+
+        [Command(0)]
+        // GetSystemEvent() -> handle<copy>
+        public ResultCode GetSystemEvent(ServiceCtx context)
+        {
+            if (context.Process.HandleTable.GenerateHandle(_asyncExecution.SystemEvent.ReadableEvent, out int _systemEventHandle) != KernelResult.Success)
+            {
+                throw new InvalidOperationException("Out of handles!");
+            }
+
+            context.Response.HandleDesc = IpcHandleDesc.MakeCopy(_systemEventHandle);
+
+            return ResultCode.Success;
+        }
+
+        [Command(1)]
+        // Cancel()
+        public ResultCode Cancel(ServiceCtx context)
+        {
+            if (!_asyncExecution.IsInitialized)
+            {
+                return ResultCode.AsyncExecutionNotInitialized;
+            }
+
+            if (_asyncExecution.IsRunning)
+            {
+                _asyncExecution.Cancel();
+            }
+
+            return ResultCode.Success;
+        }
+
+        [Command(2)]
+        // HasDone() -> b8
+        public ResultCode HasDone(ServiceCtx context)
+        {
+            if (!_asyncExecution.IsInitialized)
+            {
+                return ResultCode.AsyncExecutionNotInitialized;
+            }
+
+            context.ResponseData.Write(_asyncExecution.SystemEvent.ReadableEvent.IsSignaled());
+
+            return ResultCode.Success;
+        }
+
+        [Command(3)]
+        // GetResult()
+        public ResultCode GetResult(ServiceCtx context)
+        {
+            if (!_asyncExecution.IsInitialized)
+            {
+                return ResultCode.AsyncExecutionNotInitialized;
+            }
+
+            if (!_asyncExecution.SystemEvent.ReadableEvent.IsSignaled())
+            {
+                return ResultCode.Unknown41;
+            }
+
+            return ResultCode.Success;
+        }
+    }
+}