[SPARK-54240] Translate get array item catalyst expression to connector expression

[urosstan-db]

What changes were proposed in this pull request?

• Support conversion of catalyst GetArrayItem expression to connector expression to allow data sources to implement pushdown of this expression
• Translation is supported only in ANSI mode, because most of the data sources are ANSI compliant, and throws an exception if the index is out of bounds. Spark in non ANSI mode should not throw exception, so if expression is pushed down, behaviour is changed, and exception would be thrown, so we limit translation only in ANSI mode.

Why are the changes needed?

• To allow data sources (builtin and third-party) to implement pushdown of get array item

Does this PR introduce any user-facing change?

No

How was this patch tested?

No testing needed, since we did not implement pushdowns yet

Was this patch authored or co-authored using generative AI tooling?

No

[milastdbx]

LGTM