Properties I think are:
- MavenAttributes.P_LAST_VERIFIED (this one is triplicated as NugetGalleryFacetImpl. P_LAST_VERIFIED_DATE and RawContentFacetImpl. P_LAST_VERIFIED_DATE). These all serve same purpose: helps ProxyFacetSupport in age calculation.
Also, all these are currently saved as "format specific" attributes, which clearly they are not.
It seems this should be generalized, and the attribute should not be format specific, but "lifted" to core attributes and handled by core.