Add new option for the payment options view (APPS-1915)

[Fabtron]

it is now possible to set a headline for the payment options view the a matching navarg. The headline will only be displayed if set.

APPS-1915

How to test?

Integrate this branch into an app using the matching view/fragment and set a title via a nav arg.

Definition of Done

• Issue is linked
• All requirements of the issue are fulfilled
• Changelog is updated
• Documentation is updated
• Self-Review
• Review with the Product Owner (Release-Variante o. Minified Build)

App Tests

• Minified build has been tested (aka. Release Build)
• Environments have been taken care of (Production/Staging)
• Supported languages have been tested
• Light-/Dark-Mode has been tested
• Edge-Cases have been tested
• Android API Levels have been taken care of (minSdk?)

Testing

• Tests have been written (aka Unit-Tests, Integration-Tests, ...)