Changes to List customers (company and individual)

added the new es_ES enum value to the items/items/oneOf[subschema #1: Company customer]/billing_language response property for the response status 200

added the new es_ES enum value to the items/items/oneOf[subschema #2: Individual customer]/billing_language response property for the response status 200

added the new optional header request parameter X-Company-Id

added the required property items/items/oneOf[subschema #1: Company customer]/electronic_billing_address to the response with the 200 status

added the required property items/items/oneOf[subschema #1: Company customer]/public_administration to the response with the 200 status