Could we hide stdout for routines like abundance?

[DougBurke]

We could add a flag like quiet or redirect_stdout or ... so that we can run a routine and not see the stdout output:

>>> import xspec_models_cxc as x
>>> x.abundance('wilm')
 Solar Abundance Vector set to wilm:  Wilms, J., Allen, A. & McCray, R. ApJ 542 914 (2000) (abundances are set to zero for those elements not included in the paper).
>>> x.abundance('wilm', quiet=True)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: abundance(): incompatible function arguments. The following argument types are supported:
    1. () -> str
    2. (table: str) -> None

Invoked with: 'wilm'; kwargs: quiet=True

I think it's "more fun" than just adding a flag, as I have seen in Sherpa these messages appearing in the session where I'm running jupyter lab (i.e. who gets to define the stdout that the XSPEC model library is using?) but I don't have concrete evidence of this at this time.