Add support for named Avro schema references when translating Avro schemas to Arrow schemas

[suket123]

Support named Avro schema references

Summary

Add support for named Avro schema references when translating Avro schemas to Arrow schemas.

Problem

Valid Avro schemas can define a named record once and reuse it in later fields. The Avro parser represents these uses as Schema::Ref, which previously reached an unimplemented branch and caused a panic during deserialization.

Changes

• Resolve named schemas using Apache Avro's resolved-schema name map.
• Expand named references while preserving the containing Arrow field name and properties.
• Detect recursive references and return an explanatory error because recursive types cannot be represented directly by the generated Arrow schema.
• Add coverage for Arrow schema translation, datum deserialization, and recursive-reference errors.

Testing

cargo test --workspace

All workspace tests and documentation tests pass.

Risk

Low. The change only affects schemas containing named references; existing schema translations continue through their original paths.

Breaking Changes

None.

[Tyler-Sch]

Thanks for the PR.

Overall this looks pretty good and I can merge it after it builds.

A few things to note:

• the PR makes schema refs work on deserialize only. A round trip with serialize would fail
• The repo has a fast path (decodes straight into Arrow builders, fast_decode.rs / fast_encode.rs) and a slow path (goes through apache_avro::types::Value). Schemas with refs will always take the slow path since is_supported doesn't recognize Schema::Ref.

Otherwise, things look good. Thanks for the contribution.