Consider flexibility in "province" input (dropdown, abbreviations) [AddressComplete]

## Feedback from client

**https://cds-snc.freshdesk.com/a/tickets/30115**

> Normally we use the address information we get to generate a Purolator label. In order to do this, we need the province abbreviation (eg: QC, ON) and not the full province name. Having the Province/Territory field as a free text field also makes this more prone to error. Do you know if anything is being explored to either lock down this field or make it a dropdown with certain options?

Start by locating the AddressComplete Province/Territory field and inspect how its current free-text value is collected and submitted. Decide how the field should constrain province choices and represent abbreviations such as QC and ON; the work is done when the resulting address data supports generating a Purolator label without province-name input errors.

Written by the indexing model from the issue text.