Merge pull request #243 from hadashiA/ku/fix-none-option

Fix a bug that prevented the selection of None for Parent Reference

Author: hadashiA

VContainer/Assets/VContainer/Editor/ParentReferencePropertyDrawer.cs

@@ -13,8 +13,9 @@ public sealed class ParentReferencePropertyDrawer : PropertyDrawer
     {
         static string[] GetAllTypeNames()
         {
-            return TypeCache.GetTypesDerivedFrom<LifetimeScope>()
-                .Select(type => type.FullName)
+            return new List<string> { "None" }
+                .Concat(TypeCache.GetTypesDerivedFrom<LifetimeScope>()
+                    .Select(type => type.FullName))
                 .ToArray();
         }