[PRDP-298] feat: relax checks on anonym debtor

[alessio-cialini]

List of Changes

• Introducing relaxed controls when managing a receipt with anonymous debtor but existing payer
• Updated template data mapping accordingly in case of an anonymous debtor

Motivation and Context

https://pagopa.atlassian.net/jira/software/c/projects/PRDP/boards/440?selectedIssue=PRDP-298

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[github-actions]

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