Add unit test for scripting features

Source/Engine/Tests/TestScripting.cs

@@ -0,0 +1,23 @@
+// Copyright (c) 2012-2022 Wojciech Figat. All rights reserved.
+
+#if FLAX_TESTS
+namespace FlaxEngine
+{
+    /// <summary>
+    /// Test class.
+    /// </summary>
+    public class TestClassManaged : TestClassNative
+    {
+        TestClassManaged()
+        {
+            SimpleField = 2;
+        }
+
+        /// <inheritdoc />
+        public override int Test(string str)
+        {
+            return str.Length + base.Test(str);
+        }
+    }
+}
+#endif