[FIX] website_sale_aplicoop: payment-neutral label on the checkout button

The cart button that opens /eskaera/<slug>/checkout read "Proceed to
Checkout", and the curated eu/ca translations went further ("Ordaintzera
Joan", "Finalitza la Comanda"), all implying a payment step. With
instances running both with and without online payment, revert it to the
neutral "Review Order" in the source string, the JS labels and the es/eu/ca
translations.

Changing the msgid also drops the stale DB translation on update, so the
instance that still showed "Ir al pago" picks up the fresh term.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

website_sale_aplicoop/static/src/js/website_sale.js

@@ -1362,7 +1362,7 @@
                 error_save_draft: "Error saving cart",
                 save_cart: "Save Cart",
                 reload_cart: "Reload Cart",
-                proceed_to_checkout: "Proceed to Checkout",
+                proceed_to_checkout: "Review Order",
                 remove_item: "Remove Item",
                 confirm_order: "Confirm Order",
                 back_to_cart: "Back to Cart",