remove eventbridge wrapper if present

[masl2]

Description

Fix parsing bug: https://nhsd-jira.digital.nhs.uk/browse/CCM-13965

Messages sourced from the Account bus will have an additional eventbridge wrapper around the cloud event

Type of changes

• Refactoring (non-breaking change)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would change existing functionality)
• Bug fix (non-breaking change which fixes an issue)

Checklist

• I am familiar with the contributing guidelines
• I have followed the code style of the project
• I have added tests to cover my changes
• I have updated the documentation accordingly
• This PR is a result of pair or mob programming
• If I have used the 'skip-trivy-package' label I have done so responsibly and in the knowledge that this is being fixed as part of a separate ticket/PR.

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• I confirm that neither PII/PID nor sensitive data are included in this PR and the codebase changes.

[francisco-videira-nhs]

Looks OK to me. I wonder if it will impact Vlasis' test tests/performance/testCases/send-prepared-letter-request.spec.ts : https://github.com/NHSDigital/nhs-notify-supplier-api/pull/328/changes#diff-edc3fe4a0b3883af62846c734596d6b63b2ad6bf64292df615be1b74c5d9ce7cR36