These changes encompass the work @guillaumevernieres and
@JohnSteffen-NOAA have done recently to incorporate a constant bkg error
for satellite SST obs, assigns an obs error multiplier filter that can
be adjusted, and comments out broken in situ obs filters.

Some of the in situ obs yaml files were not indented properly when
copying over the filters for the obs error multiplier.

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Co-authored-by: Guillaume Vernieres <guillaume.vernieres@noaa.gov>