fix(*): Fixed selected column in external ESF. (#3849)

Author: gedinakova

src/app/grid/grid-external-excel-style-filtering/grid-external-excel-style-filtering.component.html

@@ -1,6 +1,6 @@
 <div class="grid__wrapper">
   <div class="flex-column">
-    <igx-select #gridColums value="ProductID" class="igSelect">
+    <igx-select #gridColums value="ProductName" class="igSelect">
       <label igxLabel>Columns:</label>
       @for (c of grid1.columns; track c) {
         <igx-select-item [value]="c.field">