romanisim: incorporate use of the crds epsf reftype #238
Description
Issue RCAL-1107 was created on JIRA by Jonathan Eisenhamer:
Currently, romanisim uses stpsf as its source for Roman PSF models. romancal has moved to using the CRDS epsf reftype for the source of PSF models. Add an option to romanisim to also use the epsf reftype as the PSF model source.