refactor: keep freezeColumn ref when changing freezing columns

Author: ghiscoding

src/app/modules/angular-slickgrid/extensions/headerMenuExtension.ts

@@ -341,6 +341,7 @@ export class HeaderMenuExtension implements Extension {
           const visibleColumns = [...this.sharedService.visibleColumns];
           const columnPosition = visibleColumns.findIndex((col) => col.id === args.column.id);
           this.sharedService.grid.setOptions({ frozenColumn: columnPosition, enableMouseWheelScrollHandler: true } as GridOption);
+          this.sharedService.frozenVisibleColumnId = args.column.id;
 
           // to freeze columns, we need to take only the visible columns and we also need to use setColumns() when some of them are hidden
           // to make sure that we only use the visible columns, not doing this would show back some of the hidden columns