React-Grid-Layout: Add preventCollision

+ Add missing `preventCollision` to `coreProps`

types/react-grid-layout/index.d.ts

@@ -178,6 +178,11 @@ declare namespace ReactGridLayout {
          */
         isRearrangeable?: boolean;
 
+        /**
+         * If true, grid items won't change position when being dragged over.
+         */
+        preventCollision?: boolean;
+
         /**
          * Uses CSS3 `translate()` instead of position top/left.
          * This makes about 6x faster paint performance.