NEXT-31047 - Improve payment handlers

[mstegmeyer]

1. Why is this change necessary?

2. What does this change do, exactly?

3. Describe each step to reproduce the issue or behaviour.

4. Please link to the relevant issues (if any).

5. Checklist

• I have rebased my changes to remove merge conflicts
• I have written tests and verified that they fail without my change
• I have created a changelog file with all necessary information about my changes
• I have written or adjusted the documentation according to my changes
• This change has comments for package types, values, functions, and non-obvious lines of code
• I have read the contribution requirements and fulfil them.

[github-actions]

	Warnings
⚠️	Please be kind and add unit tests for your new code in these files: src/Core/Checkout/Payment/Cart/PaymentHandler/PaymentHandlerType.php If you are sure everything is fine with your changes, you can resolve this warning. You can run `composer make:coverage` to generate dummy unit tests for files that are not covered

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
0 out of 2 committers have signed the CLA.

❌ lernhart
❌ mstegmeyer
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