Changes to Get interest details

added the non-success response with the status 400

added the non-success response with the status 401

added the non-success response with the status 403

added the non-success response with the status 404

added the non-success response with the status 429

the response property child_interests became required for the status 200

the response property id became required for the status 200

the response property level became required for the status 200

the response property name became required for the status 200

the id response's property pattern was changed from \d+ to ^\d+$ for the status 200

the endpoint scheme security client_credentials was added to the API

for the path request parameter interest_id, the maxLength was set to 18

endpoint added