Phone number confirmation

In case we wont force one-time buyers to create a user account it would be nice to have a phone number field (obligatory/optional - up to the Admin) and when a phone number is provided then a verification SMS code is needed to enter by the customer when placing an order (*Pro) - available when Twillio Module is enabled of course.

Such an additional customer verification can be beneficial in many ways (transactions status notifications, reminders etc). In some cases we could even collect customers phone numbers for marketing if needed (when allowed by the local law). Probably Admin could specify what country code phone numbers would be permitted to receive SMS verification.

When a customer provide a phone number we could even send a coupon code in exchange of providing phone# so customer could also see a value for sharing phone number #incentiveBonus