gh-89039: Call subclass constructors in datetime.*.replace (GH-114780)

gh-89039: Call subclass constructors in datetime.*.replace (GH-114780)

When replace() method is called on a subclass of datetime, date or time,
properly call derived constructor. Previously, only the base class's
constructor was called.

Also, make sure to pass non-zero fold values when creating subclasses in
various methods. Previously, fold was silently ignored.