Add new parser plist plugin on iOS WiFi Known Networks

[CopasAlpha26]

Added a new Plist plugin parser for extracting known WiFi network details from iOS devices.

Description:

This pull request introduces a new Plist plugin parser specifically for the com.apple.wifi.known-networks.plist file. The parser extracts relevant WiFi information such as SSID, BSSID, channels, and associated timestamps, providing enhanced visibility into known network connections on iOS devices.

The implementation includes:

• Parsing logic for extracting SSID, BSSID, channel, and timestamps like Added At and Last Associated.
• YAML formatter for producing human-readable output in the timeline.
• Test cases for verifying plugin functionality and ensuring data accuracy.
• Sample test data (com.apple.wifi.known-networks.plist) for unit testing.

Notes:

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Checklist:

• Automated checks (GitHub Actions, AppVeyor) pass
• No new new dependencies are required or l2tdevtools has been updated
• Reviewer assigned