The previous syntax used to call the conditional forecast using the extended...

The previous syntax used to call the conditional forecast using the extended path method was problematic. It does not allow to match the endogenous and the shock that are flipped. This is problematic as soon as the forecast periods are heterogeneous or the type of expectation (surprise or perfect foresight) are different. We get rid of the previous syntax.
(manually cherry picked from commit bae79d62)