Test event hook

Tests the event hook with the specified identifier. By default, we send a test event, but it's possible to request mock events of other types using the eventType parameter. This API endpoint executes synchronously and may take longer than other API calls (especially in case of unresponsive receiving servers). By default, we submit valid and syntactically events. During the configuration phase, it's useful to test how the receiver behaves with invalid data. We use the invalid parameter for this purpose. Set to any value except none, it instructs the API to intentionally break one element of the submission. In this case, the success criteria also changes. By default, we expect a 204 response, except when we're sending you a broken submission, in which case we expect a 400 in return. Please note that, when testing deliveries via intermediaries, we're not able to detect processing failures of the final recipient, only of the intermediary. For example, when testing PubSub delivery, this endpoint will return success after successfully publishing to the message queue. Testing with broken events is still useful, but you'll need to detect the failures on the receiving end.