DGS-22899 Fix support for wrapped Avro unions

[rayokota]

What

Fix support for wrapped Avro unions. For generic unions, the union is a map with a single name/value pair, with the name being the type name and the value being the union value.

Checklist

• [Y] Contains customer facing changes? Including API/behavior changes
• [Y] Did you add sufficient unit test and/or integration test coverage for this PR?
  • If not, please explain why it is not required

References

JIRA:

Test & Review

Open questions / Follow-ups

[Copilot]

Pull Request Overview

This PR fixes support for wrapped Avro unions by modifying the resolveUnion and transform functions to properly handle union types that are represented as single-entry maps (e.g., map[string]interface{}{"com.acme.Data": {...}}). The changes ensure that when transforming union fields, the wrapper structure is preserved after applying field transformations.

Key changes:

• Modified resolveUnion to detect and unwrap single-entry maps, returning both the resolved schema and the unwrapped message value
• Updated transform to reconstruct the wrapped union structure after applying transformations to the inner value
• Added comprehensive test coverage for encryption with wrapped unions

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
schemaregistry/serde/avrov2/avro_util.go	Enhanced union resolution and transformation logic to handle wrapped unions represented as single-entry maps
schemaregistry/serde/avrov2/avro_test.go	Added test case and schema definition to verify encryption/decryption works correctly with wrapped union types

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[sonarqube-confluent]

Quality Gate passed

Issues
16 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
87.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube