postgres: replace the package lib/pq with pgx (#15343)

* WIP replacing lib/pq

* change timezome param to be URI format

* add changelog

* add changelog for redshift

* update changelog

* add test for DSN style connection string

* more parseurl and quoteidentify to sdk; include copyright and license

* call dbutil.ParseURL instead, fix import ordering

Co-authored-by: Calvin Leung Huang <1883212+calvn@users.noreply.github.com>

helper/testhelpers/postgresql/postgresqlhelper.go

@@ -59,7 +59,7 @@ func connectPostgres(password string) docker.ServiceAdapter {
 			RawQuery: "sslmode=disable",
 		}
 
-		db, err := sql.Open("postgres", u.String())
+		db, err := sql.Open("pgx", u.String())
 		if err != nil {
 			return nil, err
 		}