[client] Refactor/iface pkg (#2646)

Refactor the flat code structure

client/iface/iface_destroy_bsd.go

@@ -0,0 +1,17 @@
+//go:build darwin || dragonfly || freebsd || netbsd || openbsd
+
+package iface
+
+import (
+	"fmt"
+	"os/exec"
+)
+
+func (w *WGIface) Destroy() error {
+	out, err := exec.Command("ifconfig", w.Name(), "destroy").CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("failed to remove interface %s: %w - %s", w.Name(), err, out)
+	}
+
+	return nil
+}