feat: Search UI

- Search UI with dropdown results
- Client class to handle Product Search actions and results
- Integrated Search bar into all-products and item group pages
- Run db search without redisearch
- Cleanup: [Search] change decorator names and variables
- Sider fixes

erpnext/e_commerce/product_grid.js

@@ -144,6 +144,8 @@ erpnext.ProductGrid = class {
 					${ __('Add to Cart') }
 				</div>
 			`;
+		} else {
+			return ``;
 		}
 	}
 };