Adds companies and / or people to an existing case.

This endpoint behaves the same as the Create Case endpoint when adding companies and / or people.

When adding companies, you can retrieve company registration data by setting registry_search to true, and ensuring that company_name, company_number, and jurisdiction_code are not empty. If the data cannot be found, the case is created with the provided company details. If the company registration data is found, the status, number_of_officers, and number_of_owners are updated to reflect the registry data.

Additionally, you can choose to add all the company's (human) officers to the case by setting add_directors to true. Note that this flag is applicable only when registry_search is set to true.