Can Creditmemo Flow

[swnsma]

Problem

• The main source of the motivation is the PR magento/magento2#22825
• The current implementation of verification if an order is not in a reliable state for Credit Memorandum creation.
• After discovering and fixing issues with Zero Orders, the realization becomes covered with a solid number of 'duck tapes' and need to be refactored (see listing under).
• Not all cases still covered by the current implementation.

Solution

Requested Reviewers

@akaplya @joni-jones

[magento-cicd2]

All committers have signed the CLA.