mm: Migrate service in Horizon project (#5580)

* mm: Migrate service in Horizon project

This PR migrate the `mm:u` service to the Horizon project, things were checked by some RE aswell, that's why some vars are renamed, the logic should be the same as before.

Tests are welcome.

* Lock _sessionList instead

* Fix comment

* Fix Session fields order

src/Ryujinx.Horizon/MmNv/MmNvIpcServer.cs

@@ -0,0 +1,43 @@
+using Ryujinx.Horizon.MmNv.Ipc;
+using Ryujinx.Horizon.Sdk.Sf.Hipc;
+using Ryujinx.Horizon.Sdk.Sm;
+
+namespace Ryujinx.Horizon.MmNv
+{
+    class MmNvIpcServer
+    {
+        private const int MmNvMaxSessionsCount = 9;
+
+        private const int PointerBufferSize = 0;
+        private const int MaxDomains = 0;
+        private const int MaxDomainObjects = 0;
+        private const int MaxPortsCount = 1;
+
+        private static readonly ManagerOptions _mmNvOptions = new(PointerBufferSize, MaxDomains, MaxDomainObjects, false);
+
+        private SmApi _sm;
+        private ServerManager _serverManager;
+
+        public void Initialize()
+        {
+            HeapAllocator allocator = new();
+
+            _sm = new SmApi();
+            _sm.Initialize().AbortOnFailure();
+
+            _serverManager = new ServerManager(allocator, _sm, MaxPortsCount, _mmNvOptions, MmNvMaxSessionsCount);
+
+            _serverManager.RegisterObjectForServer(new Request(), ServiceName.Encode("mm:u"), MmNvMaxSessionsCount);
+        }
+
+        public void ServiceRequests()
+        {
+            _serverManager.ServiceRequests();
+        }
+
+        public void Shutdown()
+        {
+            _serverManager.Dispose();
+        }
+    }
+}