Refactoring of acc:u0 (#701)

* Refactoring of acc:u0

- Move all account things to the account service
- More accurate IAccountServiceForApplication
- Add helper to UInt128

* FIx my engrish

* FIx my engrish #2

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

@@ -0,0 +1,68 @@
+using Ryujinx.HLE.HOS.SystemState;
+using Ryujinx.HLE.Utilities;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Ryujinx.HLE.HOS.Services.Acc
+{
+    public class AccountUtils
+    {
+        private ConcurrentDictionary<string, UserProfile> _profiles;
+
+        internal UserProfile LastOpenedUser { get; private set; }
+
+        public AccountUtils()
+        {
+            _profiles = new ConcurrentDictionary<string, UserProfile>();
+        }
+
+        public void AddUser(UInt128 userId, string name)
+        {
+            UserProfile profile = new UserProfile(userId, name);
+
+            _profiles.AddOrUpdate(userId.ToString(), profile, (key, old) => profile);
+        }
+
+        public void OpenUser(UInt128 userId)
+        {
+            if (_profiles.TryGetValue(userId.ToString(), out UserProfile profile))
+            {
+                (LastOpenedUser = profile).AccountState = AccountState.Open;
+            }
+        }
+
+        public void CloseUser(UInt128 userId)
+        {
+            if (_profiles.TryGetValue(userId.ToString(), out UserProfile profile))
+            {
+                profile.AccountState = AccountState.Closed;
+            }
+        }
+
+        public int GetUserCount()
+        {
+            return _profiles.Count;
+        }
+
+        internal bool TryGetUser(UInt128 userId, out UserProfile profile)
+        {
+            return _profiles.TryGetValue(userId.ToString(), out profile);
+        }
+
+        internal IEnumerable<UserProfile> GetAllUsers()
+        {
+            return _profiles.Values;
+        }
+
+        internal IEnumerable<UserProfile> GetOpenedUsers()
+        {
+            return _profiles.Values.Where(x => x.AccountState == AccountState.Open);
+        }
+
+        internal UserProfile GetFirst()
+        {
+            return _profiles.First().Value;
+        }
+    }
+}