* Replace payment term lines options 'last_day_following_month' and 'last_day_current_month' by two new less specific ones allowing choosing the day directly, and thus not limited to the last one anymore (semantically different). * Rename payment term line option value 'fix_day_following_month' into 'after_invoice_month' for more clarity (no semantic change). Was task 24239. Was PR #15487