[client,management] add netflow support to client and update management (#3414)

adds NetFlow functionality to track and log network traffic information between peers, with features including:

- Flow logging for TCP, UDP, and ICMP traffic
- Integration with connection tracking system
- Resource ID tracking in NetFlow events
- DNS and exit node collection configuration
- Flow API and Redis cache in management
- Memory-based flow storage implementation
- Kernel conntrack counters and userspace counters
- TCP state machine improvements for more accurate tracking
- Migration from net.IP to netip.Addr in the userspace firewall

flow/proto/generate.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+set -e
+
+if ! which realpath > /dev/null 2>&1
+then
+  echo realpath is not installed
+  echo run: brew install coreutils
+  exit 1
+fi
+
+old_pwd=$(pwd)
+script_path=$(dirname $(realpath "$0"))
+cd "$script_path"
+go install google.golang.org/protobuf/cmd/protoc-gen-go@v1.26
+go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@v1.1
+protoc -I ./ ./flow.proto --go_out=../ --go-grpc_out=../
+cd "$old_pwd"