Disable province selector on partner edit page

PT story https://www.pivotaltracker.com/story/show/79119752
- disable province selector in partner edit view
- create scenario to test that partner province & osra_num cannot be changed for persisted records
It works but is well over 80 and, to me at least, too unclear to justify using over `if..else..end`. I had tried the same but settled on the one in the PR