* Checkout class tidyup
* CheckoutProcessor placeholder
* ShippingMethodDataX to ShippingDataX
* Remove billing from checkout provider
* Remove billing data hook
* Remove billing from payment methods state
* Update typedefs
* Billing context
* Fix billing and shipping context persistence bugs
* Remove address form change
* Move phone back; another PR can deal with this
* Remove unused state
* add various hooks and improve hooks folder structure
- Also restructures hooks directory to make things a bit more organized
- Add useStoreOrder placeholder (followed up in future pull)
- Add useBillingData hook.
* implement usePaymentMethodInterface hook in payment method components
* remove obsolete hooks and implement new checkout context hooks
- add useCheckoutSubmit which exposes checkout submit button interface
- add useCheckoutRedirectUrl which exposes checkout redirect url interface
* add alias for `@woocommerce/base-utils` to jest config
* use consistent variable names for payment method id
Mike Jolley
Darren Ethier