QUALIFY statement support

[lmmx]

Unless I am mistaken this library does not provide support for QUALIFY.

Google BigQuery supports QUALIFY (GA since early 2022):

February 14, 2022

• The QUALIFY clause, which lets you filter the results of analytic functions in Google Standard SQL, is now generally available (GA).

Can this be added to the library? In the absence of this I think I am going to have to str() my nice ORM objects.

• I’m taking a look around past contribs and can see MERGE was added recently which gives some indication of how to contribute a new statement type. It is labelled ‘DDL’ but we are actually talking about DML there. Likewise I think QUALIFY is DML