Changes to Discover Portfolio Companies

added the new demo_page enum value to the data/items/attributes/source_category response property for the response status 200

added the new registration_page enum value to the data/items/attributes/source_category response property for the response status 200

api operation id discover_connection_investors removed and replaced with get_api_v3_discover_portfolio_companies_connections

for the query request parameter limit, default value was changed from 100 to 30

added the non-success response with the status 503

added the required property data/items/attributes/confidence to the response with the 200 status