Initial push to use ILive in import process

osu.Game/Database/EntityFrameworkLive.cs

@@ -0,0 +1,34 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System;
+
+namespace osu.Game.Database
+{
+    public class EntityFrameworkLive<T> : ILive<T> where T : class
+    {
+        public EntityFrameworkLive(T item)
+        {
+            Value = item;
+        }
+
+        public Guid ID => throw new InvalidOperationException();
+
+        public void PerformRead(Action<T> perform)
+        {
+            perform(Value);
+        }
+
+        public TReturn PerformRead<TReturn>(Func<T, TReturn> perform)
+        {
+            return perform(Value);
+        }
+
+        public void PerformWrite(Action<T> perform)
+        {
+            perform(Value);
+        }
+
+        public T Value { get; }
+    }
+}