fedcode-next: Link from DejaCode to curate VCIO advisory and indicate curated advisory as special advisory

[keshav-space]

Link from DejaCode to curate a VCIO problematic advisory

Use todo_count present in VCIO Advisory API response to indicate the number of problems associated with the advisory, and add a link to curate such advisory at https://<vulnerablecode>/advisories/todos/?avid=<advisory_uid>.

Integration of curated VCIO advisory as something special in DejaCode

Use curating_advisories in VCIO Advisory API response to indicate curated advisory as something special.