Changes to Update employment

added the new optional query request parameter group_tax_servicing_countries

added the optional property data/employment/country/global_payroll_supported to the response with the 200 status

added the new invited enum value to the data/employment/user_status response property for the response status 200

added the optional property data/employment/contractor_settings/charges_vat to the response with the 200 status

removed the offboarding enum value from the data/employment/status response property for the response status 200

the endpoint scheme security CustomerAPIToken AND OAuth2AuthorizationCode was added to the API

added the new optional request property partner_external_id

added the optional property data/employment/partner_external_id to the response with the 200 status

the response property data/employment/external_id became nullable for the status 200

added the optional property data/employment/bill_to_legal_entity_id to the response with the 200 status

added the optional property data/employment/engaged_by_legal_entity_id to the response with the 200 status

added the optional property data/employment/expiration_date to the response with the 200 status