VED-834 Refactor delete imms journey

[dlzhry2nhs]

Summary

• Routine Change

Key changes:

• Simple addition to README to help with setting up pre-commit hooks
• Simplified the delete controller and improved the handling of invalid immunisation ID path param
• Simplified return types of the service and repository layers. No longer any need to pass around objects we do not require.
• Minor improvement to the handling of dynamoDB errors in the repository. There was some unnecessary handling as per https://boto3.amazonaws.com/v1/documentation/api/latest/guide/error-handling.html#parsing-error-responses-and-catching-exceptions-from-aws-services (Happy to walkthrough in more detail if required.)

Note: the immunisation ID path parameter regex is very very permissive. I do not want to make any functional changes, but could be something to consider tightening later down the line. Ultimately not a major worry due to the fact that we query first before making any operation.

Reviews Required

• Dev

Review Checklist

ℹ️ This section is to be filled in by the reviewer.

• I have reviewed the changes in this PR and they fill all or part of the acceptance criteria of the ticket, and the code is in a mergeable state.
• If there were infrastructure, operational, or build changes, I have made sure there is sufficient evidence that the changes will work.
• I have ensured the changelog has been updated by the submitter, if necessary.

[github-actions]

This branch is working on a ticket in the NHS England VED JIRA Project. Here's a handy link to the ticket:

VED-834

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

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