Allow order editing permissions to be configured per country

We'd like the ability to restrict which order-editing options are available on a per-country basis, rather than applying the same set of options globally.

Many merchants work with regional checkout or fulfillment partners (e.g. Global-E) that prohibit certain order changes after an order is placed in specific countries. For example, a merchant might need to limit editing to only "apply discount code" and "cancel order" for a subset of countries, while keeping the full set of editing options available everywhere else.

Being able to configure order-editing permissions by country/region would help merchants stay compliant with regional partner restrictions without giving up flexibility in other markets.