Feature Request: Add optional field to add carrier when adding a package

[leonhuhn]

Sometimes the tracking numbers are not 100% matchable to a carrier, f.e. Hermes Germany does mostly use "H" this shipments can be used with the integration, however sometimes its just "" so it can not be automatically assigned to the carrier.

In the Web GUI of Parcels you are then able to pick one of the carriers to manually assing the shipment number, but in the integration it just fails to add the parcel because the tracking number could not be automatically fetched.

A simple solution would be to add the optional field "carrier" to the add parcel method, where the carrier can be specified

[jmdevita]

Hey @leonhuhn! I can take a look at this :) Does the 'courier' option not work in current state?

[PineappleEmperor]

I was also thinking about placeholders being assigned/updated with an estimated delivery. Placeholders are such a faff using the app/webui.