Feature 4.2: Authentication and Authorization Plugins

[ja7ad]

Develop authentication and authorization plugins for the MQTT platform. Build username/password authentication plugin, implement certificate-based authentication, topic-based ACL authorization, and a JWT/OAuth plugin framework.

Sub-issues:

• Build username/password auth plugin
• Implement certificate-based auth plugin
• Implement topic-based ACL authorization plugin
• Create JWT/OAuth plugin framework