[SPARK-56965][SQL][4.x] Add SQL parser support for TIMESTAMP_NTZ(p) and TIMESTAMP_LTZ(p)

[stevomitric]

What changes were proposed in this pull request?

This is a backport of #56041 to branch-4.x.

Adds SQL parser support for parameterized nanosecond-precision timestamp types introduced in SPARK-56876. The parser now accepts:

• TIMESTAMP_NTZ(p) -> TimestampNTZNanosType(p)
• TIMESTAMP_LTZ(p) -> TimestampLTZNanosType(p)
• TIMESTAMP(p) WITHOUT TIME ZONE (alias for TIMESTAMP_NTZ(p))
• TIMESTAMP(p) WITH LOCAL TIME ZONE (alias for TIMESTAMP_LTZ(p))
• TIMESTAMP(p) (resolves via spark.sql.timestampType session default)

with p from [7, 9]. Out-of-range precision throws INVALID_TIMESTAMP_PRECISION; negative precision is rejected by the grammar as PARSE_SYNTAX_ERROR.

The new syntax is gated behind a new internal preview flag spark.sql.timestampNanosTypes.enabled (default false).

Unparameterized TIMESTAMP, TIMESTAMP_NTZ, TIMESTAMP_LTZ, and the WITH/WITHOUT TIME ZONE variants continue to return the existing microsecond types - no behavior change.

Part of SPIP SPARK-56822 (https://issues.apache.org/jira/browse/SPARK-56822).

Why are the changes needed?

SPARK-56876 added TimestampNTZNanosType / TimestampLTZNanosType to the type system but explicitly left out SQL/DDL integration - users cannot declare these types in CREATE TABLE, CAST, or Column.cast(String) today. This PR is the parser sub-task of the SPIP and wires those spellings through DataTypeAstBuilder, behind a preview flag so the surface is opt-in until the cast/runtime sub-tasks land.

Does this PR introduce any user-facing change?

Yes made the parser changes to allow timestamps with precision.

How was this patch tested?

Extended DataTypeParserSuite

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

Generated-by: Claude Opus 4.7

[stevomitric]

@MaxGekk please take a look at this backport.

[MaxGekk]

Waiting for CI.

[MaxGekk]

I do believe the failed test is a flaky test:

[info] org.apache.spark.sql.jdbc.StarRocksIntegrationSuite *** ABORTED *** (11 minutes, 43 seconds)
[info]   The code passed to eventually never returned normally. Attempted 610 times over 10.0061540037 minutes. Last failure message: Communications link failure
[info]   
[info]   The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.. (DockerJDBCIntegrationSuite.scala:213)

[MaxGekk]

+1, LGTM. Merging to branch-4.x.
Thank you, @stevomitric.