Remove the `runBefore` property of the timeout definition object.

[cdavernas]

What would you like to be added:

Remove the runBefore property of the timeout definition object.

This issue is a pre-requirement to (or should be part of) error refactoring.
View #673 and related issues for further details.

Why is this needed:

The runBefore property should IMO absolutely go away. As a matter of fact, in addition of being a very ugly code smell/malpractice, it's a feature that has nothing to do in a timeout.
To achieve the same, one should instead define a timeout error handler that transitions to an operation state that defines a subflow action.

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.