[IMP] Propagate contract and community from pack contract to invoice

energy_communities_cooperator/views/account_move_views.xml

energy_communities_service_invoicing/__manifest__.py

energy_communities_service_invoicing/data/product_data.xml

energy_communities_service_invoicing/models/account_move.py

energy_communities_service_invoicing/models/contract.py

...y_communities_service_invoicing/report/report_invoice.xml

energy_communities_service_invoicing/utils.py

...ommunities_service_invoicing/views/account_move_views.xml

...ies_service_invoicing/wizards/service_invoicing_action.py

...vice_invoicing/wizards/service_invoicing_action_create.py