YQL-20436: Fix YqlAgg type annotation on YqlSelect

The problem is that with an implicit `GROUP BY` aggregation value should
be optional, as there can be no rows, but with an explicit `GROUP BY`
there will be at least one row, so the value should be non-optional.

This patch introduces a new option `nokey` for the `YqlAgg` callable. It
alters a type annotation behaviour. The option is promoted from the
`SqlSetItem` type annotation, while `YqlAgg` is under a lambda. To make
the promotion exactly-once, `yql_agg_promoted` `SqlSetItem` option was
added.
commit_hash:0c82df5928d5f38dcfab31676d76c083e647b3ea

0 files changed, 0 insertions, 0 deletions