[FLINK-37357][table-planner]Migrating SqlNode conversion logic from SqlNodeToOperationConversion to SqlNodeConverters

[Milesian111]

[FLINK-37357][table-planner]Migrating SqlNode conversion logic from SqlNodeToOperationConversion to SqlNodeConverters

What is the purpose of the change

This pull request dealt with a "TODO" at class "SqlNodeToOperationConversion", method "convertValidatedSqlNode":
"TODO: all the below conversion logic should be migrated to SqlNodeConverters".
And I migrated over 40 of converters to SqlNodeConverters.

Brief change log

• The Sql conversion logic codes in SqlNodeToOperationConversion are all migrated to SqlNodeConverters

Verifying this change

This change is already covered by existing tests, such as SqlDdlToOperationConverterTest and SqlDmlToOperationConverterTest .

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)

[flinkbot]

CI report:

• c9a0f26 Azure: SUCCESS

Bot commands

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