Add "except tags" or "skip tags" #1007

A problem
When you have tests for example "not for production environment", then how not to run them on production environment using annotation tags? There is no way, because there are "tags", but there are no "except tags":

--%tags(not_for_production)
select * from table(ut.run(a_tags => ?));

Suggested solution
Introduce "a_skip_tags":

--%tags(not_for_production)
select * from table(ut.run(a_skip_tags => 'not_for_production'));

Workaround
Now I can only to put such "non-production" tests in a separate folder or in a separate branch.