Add McAfee Endpoint Security ATP JSON parser

[EarthGrob]

Add McAfee Endpoint Security ATP JSON parser

Extending the mcafee plugin with a function that parses the JSON files at path sysvol/ProgramData/McAfee/Endpoint Security/ATP.

Changes

• Added path support for ATP JSON files: sysvol/ProgramData/McAfee/Endpoint Security/ATP.
• Created a new record descriptor McAfeeAtpRemediationRecord to structure the parsed data and preserve the raw JSON for forensic context.
• Added the atp() export to the McAfeePlugin.
• Implemented strict noise filtering in _iter_remediation_entries() to ensure only entries with actual threat identifiers (e.g., AlertID, ThreatName) are yielded, discarding generic software statuses.
• Implemented robust timestamp parsing (_parse_atp_timestamp()) to safely handle epoch time in seconds, milliseconds, and microseconds.
• Added comprehensive unit tests in test_mcafee.py covering successful extraction, noise filtering, timestamp boundaries, and graceful handling of malformed JSON.

How to test:
Run the included unit tests via:
pytest tests/plugins/apps/av/test_mcafee.py -v

Issue

• Closes McAfee Endpoint Security ATP parser #1282