[FLINK-38888][transform] YAML Pipeline supports item subscription of array, map and row

[Hisoka-X]

This pull request adds support for accessing elements within ARRAY and MAP types using bracket notation in SQL expressions, following the SQL standard (1-based indexing for arrays). It introduces a new utility method for item access, updates the expression parser to handle this syntax.

Due to limitations in the Calcite syntax, row access will be implemented separately later.

[Hisoka-X]

cc @yuxiqian

[yuxiqian]

Hi Hisoka, thanks for your contribution! Considering currently transform module couldn't handle nested types well, I would suggest merging #4236 first and work on this ticket later. WDYT?

Plus, there's some disabled test specs in flink-cdc-composer/src/test/resources/specs/nested.yaml. It would be great if this PR could make these cases pass.

[Hisoka-X]

Hi Hisoka, thanks for your contribution! Considering currently transform module couldn't handle nested types well, I would suggest merging #4236 first and work on this ticket later. WDYT?

OK

Plus, there's some disabled test specs in flink-cdc-composer/src/test/resources/specs/nested.yaml. It would be great if this PR could make these cases pass.

Let me enable it to verify.

[Hisoka-X]

Hi @yuxiqian , please help to review this pr. Thanks.

[yuxiqian]

Thanks for your update! Just left some comments.

[yuxiqian]

LGTM.