[FLINK-35726][table] Honor @DataTypeHint on POJO fields in type conve…

[Au-Miner]

What is the purpose of the change

Fix a regression where @DataTypeHint placed on a POJO field is silently ignored when a TypeInformation is converted to a DataType (e.g., via tableEnv.toDataStream(table, MyPojo.class).map(...) followed by fromDataStream), causing fields like Map<String, byte[]> annotated MAP<STRING, BYTES> to fall back to RAW.

Brief change log

• Add DataTypeExtractor#extractFromField(DataTypeFactory, Field) that resolves a field's DataType from its reflective @DataTypeHint, falling back to default extraction when no hint is present.
• In TypeInfoDataTypeConverter#convertToStructuredType, detect POJO fields that carry @DataTypeHint and delegate them to DataTypeExtractor#extractFromField instead of the TypeInformation-driven path; skip the subsequent primitive-bridging pass for those fields since the extractor already finalizes them.

Verifying this change

Added a PojoWithHintedMapField test POJO and a parameterized case in TypeInfoDataTypeConverterTest that asserts a HashMap<String, byte[]> field annotated @DataTypeHint("MAP<STRING, BYTES>") resolves to MAP<STRING, BYTES> bridged to HashMap instead of RAW('java.util.HashMap', ...).

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): no
• The public API, i.e., is any changed class annotated with @Public(Evolving): no
• The serializers: no
• The runtime per-record code paths (performance sensitive): no
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: no
• The S3 file system connector: no

Documentation

• Does this pull request introduce a new feature? no
• If yes, how is the feature documented? not applicable

[flinkbot]

CI report:

• 494c489 Azure: SUCCESS

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