Omit Empty Fields

[kchason]

Proposed changes

Addresses #3892.

• Adds the omitempty property to the Lines property
• Switch the reference field to a pointer to a RawStringSlice since structs themselves (e.g. RawStringSlice) don't properly follow omitempty marshaling since they aren't nilable

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)

[ehsandeep]

echo https://projectdiscovery.io | ./nuclei -id tech-detect -j -or | jq .

                     __     _
   ____  __  _______/ /__  (_)
  / __ \/ / / / ___/ / _ \/ /
 / / / / /_/ / /__/ /  __/ /
/_/ /_/\__,_/\___/_/\___/_/   v2.9.9

		projectdiscovery.io

[INF] Current nuclei version: v2.9.9 (latest)
[INF] Current nuclei-templates version: v9.5.8 (latest)
[INF] New templates added in latest release: 113
[INF] Templates loaded for current scan: 1
[INF] Targets loaded for current scan: 1
{
  "template": "http/technologies/tech-detect.yaml",
  "template-url": "https://github.com/projectdiscovery/nuclei-templates/blob/main/http/technologies/tech-detect.yaml",
  "template-id": "tech-detect",
  "template-path": "/Users/geekboy/nuclei-templates/http/technologies/tech-detect.yaml",
  "info": {
    "name": "Wappalyzer Technology Detection",
    "author": [
      "hakluke"
    ],
    "tags": [
      "tech"
    ],
    "severity": "info",
    "metadata": {
      "max-request": 1
    }
  },
  "matcher-name": "google-font-api",
  "type": "http",
  "host": "https://projectdiscovery.io",
  "matched-at": "https://projectdiscovery.io",
  "ip": "172.67.74.214",
  "timestamp": "2023-07-26T00:00:52.380353+05:30",
  "curl-command": "curl -X 'GET' -d '' -H 'Accept: */*' -H 'Accept-Language: en' -H 'User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux i686 on x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2820.59 Safari/537.36' 'https://projectdiscovery.io'",
  "matcher-status": true
}

[tarunKoyalwar]

$ echo https://projectdiscovery.io | ./nuclei -id tech-detect -j -or | jq .

                     __     _
   ____  __  _______/ /__  (_)
  / __ \/ / / / ___/ / _ \/ /
 / / / / /_/ / /__/ /  __/ /
/_/ /_/\__,_/\___/_/\___/_/   v2.9.9

		projectdiscovery.io

[INF] Current nuclei version: v2.9.9 (latest)
[INF] Current nuclei-templates version: v9.5.8 (latest)
[INF] New templates added in latest release: 113
[INF] Templates loaded for current scan: 1
[INF] Targets loaded for current scan: 1
{
  "template": "http/technologies/tech-detect.yaml",
  "template-url": "https://github.com/projectdiscovery/nuclei-templates/blob/main/http/technologies/tech-detect.yaml",
  "template-id": "tech-detect",
  "template-path": "/Users/tarun/nuclei-templates/http/technologies/tech-detect.yaml",
  "info": {
    "name": "Wappalyzer Technology Detection",
    "author": [
      "hakluke"
    ],
    "tags": [
      "tech"
    ],
    "severity": "info",
    "metadata": {
      "max-request": 1
    }
  },
  "matcher-name": "google-font-api",
  "type": "http",
  "host": "https://projectdiscovery.io",
  "matched-at": "https://projectdiscovery.io",
  "ip": "104.26.6.152",
  "timestamp": "2023-07-28T19:31:51.783437+05:30",
  "curl-command": "curl -X 'GET' -d '' -H 'Accept: */*' -H 'Accept-Language: en' -H 'User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.77 Safari/537.36' 'https://projectdiscovery.io'",
  "matcher-status": true
}
{
  "template": "http/technologies/tech-detect.yaml",
  "template-url": "https://github.com/projectdiscovery/nuclei-templates/blob/main/http/technologies/tech-detect.yaml",
  "template-id": "tech-detect",
  "template-path": "/Users/tarun/nuclei-templates/http/technologies/tech-detect.yaml",
  "info": {
    "name": "Wappalyzer Technology Detection",
    "author": [
      "hakluke"
    ],
    "tags": [
      "tech"
    ],
    "severity": "info",
    "metadata": {
      "max-request": 1
    }
  },
  "matcher-name": "cloudflare",
  "type": "http",
  "host": "https://projectdiscovery.io",
  "matched-at": "https://projectdiscovery.io",
  "ip": "104.26.6.152",
  "timestamp": "2023-07-28T19:31:51.783831+05:30",
  "curl-command": "curl -X 'GET' -d '' -H 'Accept: */*' -H 'Accept-Language: en' -H 'User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.77 Safari/537.36' 'https://projectdiscovery.io'",
  "matcher-status": true
}