Add LeakIX search module with 6 actions and bulk streaming

[Chocapikk]

Hello Metasploit Team,

This PR adds auxiliary/gather/leakix_search, a new module for the LeakIX API - a search engine focused on indexing internet-exposed services and leaked credentials/databases.

The module provides 6 actions:

• SEARCH - Paginated search with leak/service scope, up to 500 pages (10,000 results)
• HOST - Full service and leak details for a specific IP
• DOMAIN - Full service and leak details for a specific domain
• SUBDOMAINS - Subdomain enumeration with distinct IP counts and last-seen timestamps
• PLUGINS - List all available LeakIX scanner plugins (useful for building targeted queries)
• BULK - True HTTP chunked NDJSON streaming for bulk leak export (Pro API key required)

The BULK action implements manual chunked transfer-encoding dechunking and NDJSON line parsing, processing events as they arrive rather than buffering the entire response. A MAXRESULTS option caps collected results across both SEARCH and BULK. Setting DATABASE true populates the MSF services database for seamless pivoting into other modules.

Query syntax examples:

+country:"France" +port:3306
plugin:HttpOpenProxy
+software.name:"nginx" +country:"US"

Verification

• Start msfconsole
• use auxiliary/gather/leakix_search
• set LEAKIX_APIKEY <your-api-key>
• set QUERY +port:3306
• run
• Verify SEARCH returns results in a table with IP, port, protocol, host, country, organization, software, type, and source columns
• set ACTION HOST
• set TARGET_IP <ip-from-results>
• run
• Verify HOST returns services and leaks for the given IP
• set ACTION DOMAIN
• set TARGET_DOMAIN example.com
• run
• Verify DOMAIN returns services and leaks for the given domain
• set ACTION SUBDOMAINS
• run
• Verify SUBDOMAINS returns a list of subdomains with distinct IPs and last-seen dates
• set ACTION PLUGINS
• run
• Verify PLUGINS returns the list of available LeakIX scanner plugins
• set ACTION BULK
• set QUERY +country:"France"
• set MAXRESULTS 30
• run
• Verify BULK streams events and stops at MAXRESULTS limit (requires Pro API key)
• Verify setting DATABASE true populates hosts/services (hosts and services commands)
• Documentation is included