Update pystare API to include call to check for non-nominal ERFA returns.

[michaelleerilee]

ERFA routines can return errors or information about date calculations that are not completely trustworthy because they are out of the domain of the current ERFA calendar model. The calculations are still useful, but may not include leap seconds because the dates in question are too far in the future or past.

The STARE TemporalIndex system has a number of routines for checking whether ERFA has returned such non-nominal results during calculations.