Verify keyword mapping to values in astrometry database

[stscijgbot-hstdp]

Issue HLA-1275 was created on JIRA by Steve Goldman:

3.) Verify keyword mapping to values in astrometry database. For example, https://mast.stsci.edu/portal/astrometryDB/observation/read/jcsz32diq

      <{}wcsName{}>IDC_0461802dj-FIT_REL_GAIADR2
      <{}refCatalog{}>GAIADR2
      <{}nMatch{}>7                             <--  nmatches
      <{}rmsRA{}>16.69339839         <--  rms_ra     
      <{}rmsDEC{}>9.16140064         <--  rms_dec