feat: added serialized property extensions for convenience

Author: Thundernerd

Editor/Utilities/SerializedPropertyExtensions.cs

@@ -0,0 +1,22 @@
+using UnityEditor;
+
+namespace TNRD.Utilities
+{
+    internal static class SerializedPropertyExtensions
+    {
+        public static SerializedProperty ReferenceModeProperty(this SerializedProperty property)
+        {
+            return property.FindPropertyRelative("mode");
+        }
+
+        public static SerializedProperty RawReferenceProperty(this SerializedProperty property)
+        {
+            return property.FindPropertyRelative("rawReference");
+        }
+
+        public static SerializedProperty UnityReferenceProperty(this SerializedProperty property)
+        {
+            return property.FindPropertyRelative("unityReference");
+        }
+    }
+}