Support assertions in TestWorkflowEnvironment.registerDelayedCallback

[zhxnlai]

Is your feature request related to a problem? Please describe.

When assertions fail in TestWorkflowEnvironment.registerDelayedCallback, the errors in the callback are swallowed. This is counterintuitive.

For instance, I expect the following test to fail.

class MyTest {

  private val testEnv: TestWorkflowEnvironment
  
  @Test
  fun thisShouldFail() {
    testEnv.registerDelayedCallback(Duration.ofSeconds(1)) {
      assertThat(false).isTrue()
    }
    testEnv.sleep(Duration.ofSeconds(10))
  }
}

But it succeeds with an error log.

10:35:11.197 [Timer task] ERROR i.t.i.t.SelfAdvancingTimerImpl - Unexpected failure in timer callback
org.opentest4j.AssertionFailedError: 
Expecting value to be true but was false
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)

Describe the solution you'd like
Propagate the error to the test method.