[Flink] Support create and get timestamp(3) timestamp(0) type in the arctic table

[YesOrNo828]

Scenario: Create an iceberg table that has a timestamp-type column with a precision equal to 0 by Flink SQL.

Using the below DDL to create a watermark definition table like the iceberg table would be failed. create table hadoop_catalog.db.dim (id int, name string, opt timestamp(0), primary key (id) not enforced) ;

create table arctic_dim ( watermark for opt as opt - interval '5' second) like hadoop_catalog.db.dim;

org.apache.flink.table.api.ValidationException: Invalid data type of time field for watermark definition. The field must be of type TIMESTAMP(p) or TIMESTAMP_LTZ(p), the supported precision 'p' is from 0 to 3, but the time field type is TIMESTAMP(6)

The TypeToFlinkType default converts it to flink timestamp type with precision 6.

[SteNicholas]

@YesOrNo828, users could case the TIMESTAMP(p)/TIMESTAMP_LTZ(p) to TIMESTAMP(3)/TIMESTAMP_LTZ(3), which has already been verified whether the watermark definition works well. Therefore, this issue could be closed and the watermark definition could provide an example in the document.

[zhoujinsong]

@YesOrNo828, users could case the TIMESTAMP(p)/TIMESTAMP_LTZ(p) to TIMESTAMP(3)/TIMESTAMP_LTZ(3), which has already been verified whether the watermark definition works well. Therefore, this issue could be closed and the watermark definition could provide an example in the document.

@SteNicholas Thanks for your verification and I will close this issue.