Updated PR Message (for JSON field filtering)

Description

This PR enhances the existing -json output functionality by adding support for a -f (or --field) option.
Users can now specify which fields they want in the JSON output instead of always receiving all available fields.

Additionally, unlike the previous -csv PR(#1372), the option name has been updated from CSVFields to Fields for consistency across output formats.

Related Issue

Closes #1371

Related PR

#1372

Changes Introduced

• Added -f option to allow field filtering when using -json.
• Updated JSON output logic to include only specified fields.

Example Usage

Outputs only the ip and port fields instead of the full dataset.

naabu$ ./naabu -host example.com -p 80,443 -j -f "ip,port"

                  __
  ___  ___  ___ _/ /  __ __
 / _ \/ _ \/ _ \/ _ \/ // /
/_//_/\_,_/\_,_/_.__/\_,_/

		projectdiscovery.io

[INF] Current naabu version 2.3.4 (latest)
[INF] Host discovery disabled: less than two ports were specified
[INF] Running CONNECT scan with non root privileges
{"ip":"96.7.128.175","port":80}
{"ip":"96.7.128.175","port":443}
[INF] Found 2 ports on host example.com (96.7.128.175)

Looking forward to feedback