fix(core): grid service resetGrid method wasn't always resetting

- add E2E tests for the real fix that was applied in Slickgrid-Universal [PR](ghiscoding/slickgrid-universal#829)

src/app/examples/grid-state.component.ts

@@ -72,7 +72,7 @@ export class GridStateComponent implements OnInit, OnDestroy {
 
   /** Clear the Grid State from Local Storage and reset the grid to it's original state */
   clearGridStateFromLocalStorage() {
-    localStorage[LOCAL_STORAGE_KEY] = null;
+    localStorage.removeItem(LOCAL_STORAGE_KEY);
     this.angularGrid.gridService.resetGrid(this.columnDefinitions);
     this.angularGrid.paginationService!.changeItemPerPage(DEFAULT_PAGE_SIZE);
   }
@@ -180,7 +180,7 @@ export class GridStateComponent implements OnInit, OnDestroy {
 
   getData(count: number) {
     // mock a dataset
-    const tmpData = [];
+    const tmpData: any[] = [];
     for (let i = 0; i < count; i++) {
       const randomDuration = Math.round(Math.random() * 100);
       const randomYear = randomBetween(2000, 2025);

test/cypress/e2e/example16.cy.js

@@ -497,4 +497,16 @@ describe('Example 16: Grid State & Presets using Local Storage', { retries: 1 },
     cy.get('.grid-canvas-left > [style="top:0px"]').children().should('have.length', 2);
     cy.get('.grid-canvas-right > [style="top:0px"]').children().should('have.length', 3);
   });
+
+  it('should click on the reset button and have exact Column Titles position as in beginning', () => {
+    cy.get('#slickGridContainer-grid16').as('grid16');
+
+    cy.get('[data-test="reset-button"]')
+      .click();
+
+    cy.get('@grid16')
+      .find('.slick-header-columns')
+      .children()
+      .each(($child, index) => expect($child.text()).to.eq(fullEnglishTitles[index]));
+  });
 });