Refactor Payment modules

[pkarw]

What is the motivation for adding / enhancing this feature?

The current way we set the available payment methods is pretty messy. It's done using events + store methods.

To kee the backward compatibility, we should implement the parallel interface, TypeScripted for managing the payment method + full lifecycle of payment method (changed, applied etc).

The main motivation is how payment methods are implemented right now. Based on the events based logic - they're very error-prone and it's very easy to placeOrder twice - either to not place an order at all :)

What are the acceptance criteria

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Can you complete this feature request by yourself?

Additional information

[pkarw]

Related to #2405

[pkarw]

I see this one as a TS, typed, interface based approach without the event bus involved. Rather hooks like we have with the modules.

In 1.9 current order flow should still work but the new refactored one should become default with all core payment methods refactored to it.