[FLINK-37791][6/N] model sql to rel converter

[lihaosky]

What is the purpose of the change

Update rel converter to handle SqlModelCall.

Brief change log

• Update rel converter to handle SqlModelCall
• Discover ModelProvider and wrap it inside RexModelCall for optimizer
• Add rule to handle ml_predict call

Verifying this change

unit test

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)

[flinkbot]

CI report:

• 493f876 Azure: SUCCESS

Bot commands

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

[fsk119]

Thanks for your contribution. I left some comments.

[fsk119]

Do we need to introduce a new operator here? It's better we can reuse the SqlModelOperator.

[lihaosky]

Just found SqlModelOperator needs CatalogSchemaModel as argument which we don't have inside ModelProviderModel

[lihaosky]

I messed up the commits somehow and squashed the commits and force pushed...

[fsk119]

It's ok. The change in the PR is not very large.

[fsk119]

Thanks for your update.

[fsk119]

I write my idea here. You can take a look 0.0

https://github.com/apache/flink/compare/master...fsk119:flink:converter2?expand=1

[lihaosky]

I made most of the changes except reusing SqlModelOperator, I feel it's not clean to pass it along the stack and RexTableArgCall also use a new one: https://github.com/apache/flink/blob/master/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/calcite/RexTableArgCall.java#L48

[fsk119]

Thanks for your update. I left some comments.

[fsk119]

Thanks for your update. I left some minor suggestions.

[fsk119]

LGTM. Merging when CI passes...