[FLINK-29720][hive] Supports hive average function by native implemetatoin

[Tartarus0zm]

What is the purpose of the change

Supports native hive avg function for hive dialect.

Brief change log

• Supports native hive avg function for hive dialect

Verifying this change

This change added tests and can be verified as follows:

• HiveDialectAggITCase
• HiveDialectQueryPlanTest

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? (yes)
• If yes, how is the feature documented? (JavaDocs)

[Tartarus0zm]

@lsyldliu @luoyuxia @godfreyhe @beyond1920 hello, please take a look, if you have time, thanks

[flinkbot]

CI report:

• cfd5912 Azure: PENDING

Bot commands

The @flinkbot bot supports the following commands:

• @flinkbot run azure re-run the last Azure build

[Tartarus0zm]

Repeated with #21601