The "Update BoM" button action was moved from `mrp_plm` to `mrp` so it
can be displayed if the BoM was updated now. This action can be called
for confirmed MO now.
Each time a change is done on a BoM, all the draft and confirmed MOs
using this BoM will be notified the BoM changed, thanks to a new boolean
field, `bom_has_been_updated`.
An exception however: if the MO is confirmed and the BoM's product was
changed, the MO shouldn't have the "Update BoM" button displayed.
Otherwise, it would change the finished product of a confirmed MO.
Also, it's important to notice than due to a limitation, only changes
done at the BoM level will mark it as modified. That means that
modifying subrecords in their own views (for example, adding steps in a
BoM's operation) will not mark the BoM as updated !
See odoo/enterprise#35969
task-3089368
Part-of: odoo/odoo#110227
svs-odoo
d7392829c7