account: Adds AccountManager (#2184)

* account: Adds Account Manager

In a way to have Custom User Profiles merged in master faster, this PR adds a `AccountManager` class (based on `AccountUtils` class) and the following changes have been made:
- Adds a "default profile values" which were the old hardcoded ones.
- The image profile is moved to the Account service folder.
- The hardcoded UserId for the savedata is now using the `AccountManager` last opened one.
- The DeviceId in Mii service is changed to the right value (checked by REd sys:set call).

* Fix csproj

* Addresses gdkchan's comments

* Fix UserProfile fields

* Fix mii GetDeviceId()

* Update Ryujinx.HLE.csproj

Ryujinx.HLE/HOS/Services/Sdb/Pdm/QueryService/QueryPlayStatisticsManager.cs

@@ -25,7 +25,7 @@ namespace Ryujinx.HLE.HOS.Services.Sdb.Pdm.QueryService
 
             if (byUserId)
             {
-                if (!context.Device.System.State.Account.TryGetUser(userId, out _))
+                if (!context.Device.System.AccountManager.TryGetUser(userId, out _))
                 {
                     return ResultCode.UserNotFound;
                 }