Today we use polling on FailPoint counts to "wait" on a FailPoint.

Move to a formal cross process event. Create a Named Semaphore on linux and Global Event on Windows. Pass the Semaphore/Event name to the Server. Have the Server signal when the FailPoint fires. This allows test code to Wait on a Failpoint.

This should be bi-directional: failpoint should be able to wait for a continuation from the client. Client can wait for failpoint trigger.