Add `sum-where` [ci all]

...ivers/druid/src/metabase/driver/druid/query_processor.clj

...ivers/mongo/src/metabase/driver/mongo/query_processor.clj

src/metabase/driver/sql/query_processor.clj

src/metabase/mbql/normalize.clj

src/metabase/mbql/schema.clj

src/metabase/query_processor/middleware/annotate.clj

test/metabase/query_processor_test/count_where_test.clj

test/metabase/query_processor_test/sum_where_test.clj