Make whois installation optional and add ability to disable whois lookup in domain lookup modules

[getpinga]

Problem

Currently, the registrar requires whois to be installed and enabled, and domain lookup modules always perform both whois and RDAP lookups.

Proposed Solution

• Make whois installation optional during the setup process.
• Update domain lookup modules to provide an option to disable whois lookups and only use RDAP for queries.
• Ensure clear documentation and configuration options for enabling/disabling whois support globally and per-module.

Acceptance Criteria

• User can install and run registrar with just RDAP lookups (whois not installed)
• Configuration option (global or per-module) exists to disable whois lookups
• Documentation covers new options and their usage