Extending advanced filtering

[Mzack9999]

Proposed changes

This PR implements metadata addition as described in #2826. The new fields can be used as follows:

nuclei -tc protocol=='dns'
nuclei -tc contains(http_methods,'GET')
nuclei -tc len(bodies)>0
nuclei -tc contains(matcher_types,'word')
nuclei -tc contains(extractor_types,'regex')
nuclei -tc contains(description,'wordpress')

Notes

Docs update tracked at projectdiscovery/nuclei-docs#104

Checklist

• Pull request is created against the dev branch
• All checks passed (lint, unit/integration/regression tests etc.) with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

[tarunKoyalwar]

lgtm!

[ehsandeep]

probably missed in #2374. Do you think we can make this case insensitive? @Mzack9999

$./nuclei -tc "contains(description,'wordpress')" -tl -silent | wc
       7
$./nuclei -tc "contains(description,'WordPress')" -tl -silent | wc
     376