Move Common functionality to Core project & rendering and Model support as well

PckStudio.Core/Extensions/BlendMode.cs

@@ -0,0 +1,14 @@
+namespace PckStudio.Core.Extensions
+{
+    public enum BlendMode
+    {
+        Add,
+        Subtract,
+        Multiply,
+        Average,
+        DescendingOrder,
+        AscendingOrder,
+        Screen,
+        Overlay
+    }
+}