[FIX] point_of_sale: performance improvement to read one session

The fact the pos config name get was doing
`config.session_ids[0].state`
led to the prefetch of fields of all the session_ids of this config
on reading `config_id` for the session form

Therefore, if a pos config had 1000 sessions,
it was prefetching fields of 1000 sessions when you actually
wanted only one session to display in the form.
Among others, the `picking_count` field which is
not stored and quite heavy to compute

In term of time, it went from 1 minute to 1 second
to open the form view of one pos session.

0 files changed, 0 insertions, 0 deletions