syzbot: track missing CVE fixes

[tarasmadan]

Is your feature request related to a problem? Please describe.
Upstream attach the CVE number to patches now.
Syzbot knows what patch fixes what reproducer.
It means missing patches are the missing CVE fixes if patch has associated CVE number and syz tag.
It can amplify the "missing patches" page value.
And it adds one more use-case for the exported reproducers.