Implement mii:u and mii:e entirely (#955)

* Implement mii:u and mii:e entirely

Co-authored-by: AcK77 <Acoustik666@gmail.com>

This commit implement the mii service accurately.

This is based on Ac_k work but was polished and updated to 7.x.

Please note that the following calls are partially implemented:

- Convert: Used to convert from old console format (Wii/Wii U/3ds)
- Import and Export: this is shouldn't be accesible in production mode.

* Remove some debug leftovers

* Make it possible to load an arbitrary mii database from a Switch

* Address gdk's comments

* Reduce visibility of all the Mii code

* Address Ac_K's comments

* Remove the StructLayout of DatabaseSessionMetadata

* Add a missing line return in DatabaseSessionMetadata

* Misc fixes and style changes

* Fix some issues from last commit

* Fix database server metadata UpdateCounter in MarkDirty (Thanks Moose for the catch)

* MountCounter should only be incremented when no error is reported

* Fix FixDatabase

Co-authored-by: Alex Barney <thealexbarney@gmail.com>

Ryujinx.HLE/HOS/Services/Mii/DatabaseSessionMetadata.cs

@@ -0,0 +1,24 @@
+using Ryujinx.HLE.HOS.Services.Mii.Types;
+
+namespace Ryujinx.HLE.HOS.Services.Mii
+{
+    class DatabaseSessionMetadata
+    {
+        public uint  InterfaceVersion;
+        public ulong UpdateCounter;
+
+        public SpecialMiiKeyCode MiiKeyCode { get; private set; }
+
+        public DatabaseSessionMetadata(ulong updateCounter, SpecialMiiKeyCode miiKeyCode)
+        {
+            InterfaceVersion = 0;
+            UpdateCounter    = updateCounter;
+            MiiKeyCode       = miiKeyCode;
+        }
+
+        public bool IsInterfaceVersionSupported(uint interfaceVersion)
+        {
+            return InterfaceVersion >= interfaceVersion;
+        }
+    }
+}