As an open source user settings is already pre-populated (never null)

[chrisjsimpson]

Is your feature request related to a problem? Please describe.
When using Subscribie standalone , (without Subscribie Deployer) the settings model is empty by default which causes:

File "subscribie/utils.py", line 58, in get_shop_default_country_code
 default_country_code = settings.default_country_code
 AttributeError: 'NoneType' object has no attribute 'default_country_code'

Describe the solution you'd like

During blueprint first run, pre-populate the Settings model with a row of settings, with the column insertion defaults.

1. replace before_app_first_request with record_once because before_app_first_request has been deprecated (unable to find reason) record_once may or may not be the correct replacement*.
   

   subscribie/subscribie/views.py

   Line 48 in f4b9115

   @bp.before_app_first_request

*Update: record_once not used- instead we've moved initialisation logic to new bootstrap_app.py and passed an application context to that.

Describe alternatives you've considered

Additional context
We crudely populate Settings model here but that's programming by coincidence and should also be removed.