[FEATURE] Fill finding values into info description, impact and remediation

[mazzz3r]

Please describe your feature request:

{{...}} placeholders in description, impact and remediation, filled for each finding with what requests already use: extractors, payloads, variables, DSL helpers, and result fields such as host, port and matched-at.

redis-default-logins with a version extractor and this description:

description: |
  Redis {{version}} on {{host}}:{{port}} accepted the password "{{replace_regex(passwords, '^(.{2}).*$', '$1***')}}".

reports this against Redis 7.0.15 with requirepass admin:

Redis 7.0.15 on 127.0.0.1:6379 accepted the password "ad***".

The other info fields stay static. An unknown placeholder or a failing expression leaves the text as written.

Describe the use case of this feature:

Today every redis-default-logins finding says "Redis service was accessed with easily guessed credentials.", and the host, version and password have to be dug out of meta and the raw response. Reports, issue trackers and SARIF all print the description, so with the values in it each finding reads on its own.

Filled text goes through -redact. SARIF keeps the template's text on the rule and the filled text on each result. Templates with placeholders in info aren't clustered, because a cluster shares the first template's event.

No template in nuclei-templates has {{ or § in these fields, so existing output doesn't change.

The implementation is in #7940.

[mazzz3r]

Merged, thanks!