Enhancement idea: configuration option to write packets in pcapng format

Npcap inherits WinPcap's interface, which means packets are written in something resembling the "pcap" file format (https://datatracker.ietf.org/doc/html/draft-gharris-opsawg-pcap). If we supported writing the extensible pcapng format (https://datatracker.ietf.org/doc/html/draft-tuexen-opsawg-pcapng), we could do things like:

• Report statistics directly in the packet stream, including adding new statistics as we like without being concerned about backwards compatibility.
• Avoid clearing the entire packet buffer when a capture configuration change is made, preferring instead to inject a block of appropriately descriptive metadata indicating exactly when the change took place (e.g. a new packet filter, etc.)
• Report diagnostic info directly in the packet stream, such as changes to the adapter reported via Status Indications or average buffer occupancy.

Start by reviewing Npcap's existing packet-writing path and comparing its current output with the pcap and pcapng specifications linked in the issue. Define how statistics, configuration-change metadata, and adapter diagnostics should be represented, then verify that captures remain readable and preserve those events in the packet stream.