fix(header): hidding column from header menu after reordering fixes #62

- we should always use the SlickGrid getColumns when doing any search of column index. This is especially true after changing the order, get the getColumns() should always be the reference

Author: Ghislain Beaulac

src/app/modules/angular-slickgrid/services/controlAndPlugin.service.ts

@@ -420,9 +420,9 @@ export class ControlAndPluginService {
 
   /** Hide a column from the grid */
   hideColumn(column: Column) {
-    if (this._grid && this.visibleColumns) {
+    if (this._grid && this._grid.getColumns && this._grid.setColumns) {
       const columnIndex = this._grid.getColumnIndex(column.id);
-      this.visibleColumns = this.removeColumnByIndex(this.visibleColumns, columnIndex);
+      this.visibleColumns = this.removeColumnByIndex(this._grid.getColumns(), columnIndex);
       this._grid.setColumns(this.visibleColumns);
     }
   }