Handle NextRetryDelay option in workflow task failures

[gow]

What changed?

Workflow tasks can now return an application error with NextRetryDelay option to customize when the workflow task will be retried again.

  return temporal.NewApplicationError(
    "some retryable error",
    "SomeType",
    temporal.ApplicationErrorOptions{NextRetryDelay: 2 * time.Minute},
  )

Why?

Currently Activity tasks can customize the next retry time. This is bringing the same feature to workflow tasks as well.

How did you test it?

Added unit tests. Also added a test to assert next retry delay customization in activities.

Potential risks

Documentation

Is hotfix candidate?

No