Changes to Create sandbox (v2)

the request property network/allowPublicTraffic became nullable

the allowPublicTraffic request property default value true was removed

added the new optional header request parameter Idempotency-Key

added the new optional request property network/dnsServers

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 409

added the non-success response with the status 422

added the new optional request property network/egressProxy/tls

endpoint added