Change Bill to Customer text on pdf invoice with guest orders.

[bfjare]

When a user checkouts as a guest with just an email. The "Bill to" customer info reads Customer for "Craft user with ID XXXXX".

My client doesn't really like this on invoices when sending it to a customer. I think the order is easy to reference and cross check without this in the invoice. The suggestion is if the customer doesn't have a name on the order to not pass data or not show this line.

If stripe requires this information I would suggest a different value here. Perhaps "{site name} guest order".