Suggestion for delivery address on delivery notes

@lubos this update does not work as needed. there is a bug.

if a delivery address is set for a customer, it is shown when creating a delivery note.
but when a delivery address is not set for a customer, the original billing address is not shown on the delivery note. only the customer name and business identifier is shown.

this is exactly what the Indian users need.
http://www.cbec.gov.in/resources//htdocs-cbec/gst/invoice-gst-rules17052017.pdf

all tax invoice should have the billed and shipped to party clearly mentioned.

@lubos if the new Delivery Address field under Customers tab can be converted as a custom field with the ability to rename its heading would be really helpful. else, both the sales invoice and delivery notes forms should be modified to include both billing and shipping fields separately.