🚀 Native SNMP Provider with Signal Denoising

This PR implements a native SNMP Trap listener for Keep. Unlike basic implementations, this version includes a sliding-window denoising engine to prevent alert fatigue from flapping network devices.

✨ Key Features:

• Native Async Listener: Built on pysnmp, requiring no external daemons.
• Signal Denoising: Intelligent logic to identify and drop duplicate traps within a configurable window (e.g. 10s).
• Intelligent Mapping: Automated OID-to-Severity mapping (e.g., linkDown -> CRITICAL).
• Robust Lifecycle: Implements dispose() for clean resource management and _query() to satisfy abstract base requirements.

✅ Verification:

Verified in WSL2 environment. Included unit tests cover:

1. Denoising Logic: Proved duplicate traps are dropped within the window.
2. Severity Mapping: Proved correct conversion of OIDs to AlertSeverity.

I have attached a technical demo of the Native SNMP Provider. It covers:

1. Signal Denoising Logic: Sliding-window duplicate suppression.
2. Lifecycle Management: Clean implementation of dispose().
3. Unit Test Verification: test_denoising_logic and test_severity_mapping passing.

https://github.com/user-attachments/assets/c86cfc5e-af6e-42b2-b28f-a1fa97997f37

Linked Issue: Closes #2112

/claim #2112