VED-837 Refactor get imms by identifier and search endpoints

[dlzhry2nhs]

Summary

• Routine Change

See linked ticket VED-837 for full summary of what has been moved where. In brief:

• search imms handler logic which decides which endpoint has been called is all moved into controller.
• controller layer vastly simplified. Parameter parsing is done once rather than duplicated across different paths through the code. It then decides whether it is an identifier or patient + vacc type search and the performs the relevant validation.
• service layer has taken some of the business logic from the controller e.g. preparation of the search bundle, adding the patient item, adding operationOutcome if relevant etc.
• very minor refactoring and tidying up at the repository layer.

Additionally:

• tried to use FHIR entities as far as possible at the business logic/service layer.
• IMPORTANT - now only accept query params at the GET /Immunization endpoint and xxx-www-form-urlencoded body at the POST /Immunization/_search endpoint.
• additionally, 2 minor adjustments to error messages/scenarios. These are summarised in the ticket.

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 of the acceptance criteria of the ticket.
• If there were infrastructure, operational, or build changes, I have made sure there is sufficient evidence that the changes will work.
• If there were changes that are outside of the regular release processes e.g. account infrastructure to setup, manual setup for external API integrations, secrets to set, then I have checked that the developer has flagged this to the Tech Lead as release steps.
• I have checked that no Personal Identifiable Data (PID) is logged as part of the changes.

[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-837

[dlzhry2nhs]

Was previously unused code. I have resurrected it, and got rid of the .lower() -> not needed.

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
92.5% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud