provider details logic update and test fixes

[kalbfled]

User Story - Business Need

• Ticket is understood, and QA has been contacted (if the ticket has a QA label).

#1436 ended with x-failing a number of tests failing when run sequentially and skipping another that leaves artifacts in the database. This ticket is to completely overhaul ProviderDetail and ProviderDetailHistory tests. We removed SMS priority swapping in #944 and we have a follow-on to further clean that up with #962 .

User Story(ies)

As a Notify team member,
I want to ensure we have provider logic that makes sense
So that we provide the best service.

Additional Info and Resources

• Flowchart

Engineering Checklist

• Best/appropriate provider logic is identified and implemented by testing paths of this flowchart
• Remove all xfail decorators related to this ticket. (grep "TODO 1631" to find them)

Acceptance Criteria

• All tests pass and leave no database artifacts
• TODO.*1631 shows no results