Add possibility to choose delivery service manually

[diogocnunes]

Hi!

In my case, I know that my order will be delivered by SEUR, but when I enter the order number (for your tests, it's 830003563458), even when I enter my postal code, an order appears that has nothing to do with mine (from Phillipines). In this case, I would like to be able to choose, among the suggestions, the one that represents the one I want to see.

Congratulations on the excellent work!