[FIX] fields: `compute_sudo` defaults to True for stored fields only

The default `compute_sudo=True` makes sense for recomputing stored
fields that are indirectly related to a business operation.  This
ensures that the recomputation of the field does not break an operation
that is not aware of the fields to recompute.

However, computing non-stored fields in superuser mode is usually not
necessary.  It even leads to unexpected values: counting a partner's
sales orders does not give the same result in superuser mode as in
normal mode.  That is why non-stored fields are not computed in
superuser mode by default.

[FIX] account, delivery, event, hr_recruitment, point_of_sale, stock:
adapt the model definition to make all fields with the same compute
method have the same value for `compute_sudo`.

[FIX] sale: split the computation of `invoice_ids`, `invoice_count`
(non-stored) and `invoice_status` (stored), as no code is actually
shared.

closes odoo/odoo#38805

Signed-off-by: Olivier Dony (odo) <odo@openerp.com>