Integrate CIRCL.lu's KEV standards

[todb]

CIRCL.lu is publishing several KEV lists now.

The standard: https://gcve.eu/bcp/gcve-bcp-07/

The lists: https://vulnerability.circl.lu/known-exploited-vulnerabilities-catalog/

I imagine it's possible and desirable to integrate this, at least with respect to the CISA KEV (though right now, the CISA KEV replication there doesn't seem to cite sources OTHER than the CISA KEV itself).

Watching the discussion here: https://discourse.ossbase.org/t/kev-known-exploited-vulnerabilities-potential-format-bcp-07/744/29