[FIX] res_partner_operating_unit: operating_unit_ids group negation

Ensures `operating_unit_ids` can be used in `domain`
despite being visible only to users in the `operating_unit.group_multi_operating_unit` group.

Fixes:
```
Field 'operating_unit_ids' used in domain of <field name="property_product_pricelist"> (
  [
    '|',
    ('operating_unit_id', 'in', operating_unit_ids),
    ('operating_unit_id', '=', False),
  ]
) is restricted to the group(s) operating_unit.group_multi_operating_unit.
```

Author: vvrossem

res_partner_operating_unit/views/res_partner_view.xml

@@ -14,6 +14,11 @@
                     options="{'no_create': True}"
                     widget="many2many_tags"
                 />
+                <field
+                    name="operating_unit_ids"
+                    groups="!operating_unit.group_multi_operating_unit"
+                    invisible="1"
+                />
             </field>
         </field>
     </record>
@@ -28,6 +33,11 @@
                     groups="operating_unit.group_multi_operating_unit"
                     widget="many2many_tags"
                 />
+                <field
+                    name="operating_unit_ids"
+                    groups="!operating_unit.group_multi_operating_unit"
+                    column_invisible="1"
+                />
             </field>
         </field>
     </record>