Currently every library defines their own set of test data. eg:

• standard-webhooks/libraries/javascript/src/webhook.test.ts

  Lines 7 to 9 in ff0f07f

  	const defaultMsgID = "msg_p5jXN8AQM9LWM0D4loKWxJek";
  	const defaultPayload = `{"test": 2432232314}`;
  	const defaultSecret = "MfKQ9r8GKYqrTwjUPD8ILPZIo2LaLaSw";

• standard-webhooks/libraries/go/webhook_test.go

  Lines 13 to 15 in ff0f07f

  	var defaultMsgID = "msg_p5jXN8AQM9LWM0D4loKWxJek"
  	var defaultPayload = []byte(`{"test": 2432232314}`)
  	var defaultSecret = "MfKQ9r8GKYqrTwjUPD8ILPZIo2LaLaSw"

• etc.

We should at least consider a common set of data to be sure all implementations behave the same.