[IMP] energy_selfconsumption: invoicing energy delivered

Trello Card

Changelog

• [IMP] energy_selfconsumption: new wizard invoicing_wizard to manually generate the invoices for the energy delivered selfconsumption projects.
• [IMP] energy_selfconsumption: action to invoice energy delivered contracts, can only be applied to the same period (start and end)
• [IMP] energy_selfconsumption: view of contracts grouped by period (start and end)
• [IMP] energy_selfconsumption: contract io.cron will not get contracts related to energy delivered projects.
• [IMP] energy_selfconsumption: contract.contract will now save last period invoiced.