Invoices plugin

Invoice price is calculated based on its items. For each object that should be added to invoice (invoice item source) should be created a separate model.

Business logic for invoice item creation and registration should be covered in a registrator in the module registrators.py.

Invoice items creation and termination should be triggered in handlers that reacts on items sources deletion or save. RegistrationManager should be used in handlers.

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Last update: 2023-10-23