fix: refresh available and selection grid items on orientation change

Close #117

Author: Felipe Lang

src/main/java/com/flowingcode/vaadin/addons/twincolgrid/TwinColGrid.java

@@ -339,6 +339,8 @@ public TwinColGrid<T> withOrientation(Orientation orientation) {
     if (this.orientation != orientation) {
       this.orientation = orientation;
       updateContainerLayout();
+      available.grid.getDataProvider().refreshAll();
+      selection.grid.getDataProvider().refreshAll();
     }
     return this;
   }