[client] Refactor/iface pkg (#2646)

Refactor the flat code structure

client/iface/iface_destroy_windows.go

@@ -0,0 +1,32 @@
+//go:build windows
+
+package iface
+
+import (
+	"fmt"
+	"os/exec"
+
+	log "github.com/sirupsen/logrus"
+)
+
+func (w *WGIface) Destroy() error {
+	netshCmd := GetSystem32Command("netsh")
+	out, err := exec.Command(netshCmd, "interface", "set", "interface", w.Name(), "admin=disable").CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("failed to remove interface %s: %w - %s", w.Name(), err, out)
+	}
+	return nil
+}
+
+// GetSystem32Command checks if a command can be found in the system path and returns it. In case it can't find it
+// in the path it will return the full path of a command assuming C:\windows\system32 as the base path.
+func GetSystem32Command(command string) string {
+	_, err := exec.LookPath(command)
+	if err == nil {
+		return command
+	}
+
+	log.Tracef("Command %s not found in PATH, using C:\\windows\\system32\\%s.exe path", command, command)
+
+	return "C:\\windows\\system32\\" + command + ".exe"
+}