Add database picker master/slave when QueryRow is called

[kushtrimjunuzi]

This is useful when using postgres database, github.com/lib/pq driver does not implement LastInsertId() func so there is no other way to get auto-incremental id by running Exec, which means we have to use QueryRow to get that id, for this reason we need a conditional database picker by looking at some args such as query or args part of QueryRow func.