* Add new global setting for currency options
- Moving away from external configuration
- Refactor currency support code into new file
* Refactoring
- Move functions into currency.py
* Limit choices for default currency
* Improve validation
* Adds data migration for existing currency selection
* Docs updates
* Remove currency config from external settings
* bump api version
* Add debug message
* Add unit tests
* Fix after_change_currency func
* Fix after_change_currency func
* Revert change to after_chance_currency
* Revert other change