chore(*): fix pipe test and lint errors

Author: mddragnev

projects/igniteui-angular/src/lib/grids/pivot-grid/pivot-grid.component.ts

@@ -18,7 +18,7 @@ import { GridType } from '../common/grid.interface';
 import { IgxGridNavigationService } from '../grid-navigation.service';
 import { IgxGridCRUDService } from '../common/crud.service';
 import { IgxGridSummaryService } from '../summaries/grid-summary.service';
-import { IPivotConfiguration, IPivotDimension, IPivotKeys, PivotDimensionType } from './pivot-grid.interface';
+import { IPivotConfiguration, IPivotKeys, PivotDimensionType } from './pivot-grid.interface';
 import { IgxPivotHeaderRowComponent } from './pivot-header-row.component';
 import { IgxColumnGroupComponent } from '../columns/column-group.component';
 import { IgxColumnComponent } from '../columns/column.component';