[FIX] point_of_sale: improve product search in large databases

Before this commit, searching for a product in the product screen was
problematic when dealing with large databases. The search function was
triggered too frequently, leading to performance issues.

With this commit, I have increased the debounce time for the product
search. This reduces the frequency of search operations when user is
typing.

opw-3788796

closes odoo/odoo#156806

Signed-off-by: Vlad Stroia (vlst) <vlst@odoo.com>

addons/point_of_sale/static/src/app/screens/product_screen/product_list/product_list.xml

@@ -16,7 +16,7 @@
                     isSmall="ui.isSmall"
                     placeholder="'Search products...'"
                     icon="{type: 'fa', value: 'fa-search'}"
-                    debounceMillis="100" />
+                    debounceMillis="500" />
             </div>
             <div class="product-list-container flex-grow-1 overflow-y-auto">
                 <div t-if="productsToDisplay.length != 0 and pos.posHasValidProduct()" t-attf-class="product-list {{this.pos.productListViewMode}} p-1">