### What changes were proposed in this pull request?
Remove the YEAR, MONTH, DAY, HOUR, MINUTE, SECOND keywords. They are not useful in the parser, as we need to support plural like YEARS, so the parser has to accept the general identifier as interval unit anyway.
### Why are the changes needed?
These keywords are reserved in ANSI. If Spark has these keywords, then they become reserved under ANSI mode. This makes Spark not able to run TPCDS queries as they use YEAR as alias name.
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
Added `TPCDSQueryANSISuite`, to make sure Spark with ANSI mode can run TPCDS queries.
Closes#29560 from cloud-fan/keyword.
Authored-by: Wenchen Fan <wenchen@databricks.com>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
ccc0250a08