New app configuration to control billing address being required

Spree::Config.billing_address_required now can be used to force billing address
to be required and also gives the ability to custom payment methods to override
this method and specify what they need

core/app/models/spree/payment_method.rb

@@ -223,6 +223,10 @@ def source_required?
       true
     end
 
+    def billing_address_required?
+      Spree::Config.billing_address_required
+    end
+
     # Custom gateways can redefine this method to return reusable sources for an order.
     # See {Spree::PaymentMethod::CreditCard#reusable_sources} as an example
     def reusable_sources(_order)

core/lib/spree/app_configuration.rb

@@ -96,6 +96,13 @@ class AppConfiguration < Preferences::Configuration
     #   @return [Boolean] Whether use of an address in checkout marks it as user's default
     preference :automatic_default_address, :boolean, default: true
 
+    # @!attribute [rw] billing_address_required
+    #   Controls whether billing address is required or not from payment methods
+    #   by default, can be overridden at payment method.
+    #   (default: +false+)
+    #   @return [Boolean]
+    preference :billing_address_required, :boolean, default: false
+
     # @!attribute [rw] binary_inventory_cache
     #   Only invalidate product caches when they change from in stock to out of
     #   stock. By default, caches are invalidated on any change of inventory