Added AddMethod and Default x,y,width,height on Add

src/Interfaces/IAvailableContainer.ts

@@ -1,11 +1,15 @@
 import React from 'react';
+import { AddMethod } from '../Enums/AddMethod';
 import { XPositionReference } from '../Enums/XPositionReference';
 
 /** Model of available container used in application configuration */
 export interface IAvailableContainer {
   Type: string
-  Width: number
-  Height: number
+  Width?: number
+  Height?: number
+  DefaultX?: number
+  DefaultY?: number
+  AddMethod?: AddMethod
   XPositionReference?: XPositionReference
   Style: React.CSSProperties
 }