[IMP] Metadata strategy on sale order contract activation

energy_communities_service_invoicing/__manifest__.py

...ommunities_service_invoicing/components/contract_utils.py

...munities_service_invoicing/components/sale_order_utils.py

...y_communities_service_invoicing/models/pack_type_mixin.py

energy_communities_service_invoicing/models/sale_order.py

..._communities_service_invoicing/views/sale_order_views.xml

...vice_invoicing/wizards/service_invoicing_action_create.py