quic: analyzer: Support QUIC v2

QUIC v2 changed the version *and* the packet type enumeration to prevent
protocol ossification. Use an intermediary unit to handle the difference.

scripts/base/protocols/quic/consts.zeek

@@ -3,5 +3,6 @@ module QUIC;
 export {
 	const version_strings: table[count] of string = {
 		[0x00000001] = "1",
+		[0x6b3343cf] = "quicv2",
 	} &default=function(version: count): string { return fmt("unknown-%x", version); };
 }