Bring `bibxml2` dataset up to date (in the future)

[ronaldtse]

W3C, ISO, ITU, ANSI, FIPS, CCITT [previous name of ITU], IEEE, OASIS, PKCS

W3C, ISO, ITU, FIPS are all supported by Relaton (the latter two especially are provided by the authoritative parties).

OASIS has indicated they are willing to provide bibdata (in a separate project, but the data can also be useful for IETF).

We will need to figure out CCITT documents (legacy docs from ITU).

PKCS has no authority now (they were published by RSA) so we can just move those content into a static dataset.

ANSI we will need to figure out.

Originally from https://github.com/ietf-ribose/bibxml-service/issues/10#issuecomment-952764950