feat: introducing security monitoring feature in NGINX Agent

[mohamed-gougam]

Proposed changes

Introduce a plugin and an extension responsible for collecting, processing, and streaming Security Violation Events.

Key Features:

• The monitoring extension starts a Syslog server and listens to messages from NGINX App Protect
• The Syslog messages are parsed, and a SecurityViolationEvent proto message is created
• The SecurityViolationEvents are batched and sent as a part of EventReport

Main Contributor: @mohamed-gougam

Testing

• An initial testing and validation of the feature has been completed to verify the end-to-end working of the feature with the NMS Control Plane
• Unit and Component tests are added where applicable

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING document
• If applicable, I have added tests that prove my fix is effective or that my feature works
• If applicable, I have checked that any relevant tests pass after adding my changes
• I have updated any relevant documentation (README.md)