pkg: add a function to generate chain names

Adds a function to generate chain names for use in iptables and
ports all drivers to use that function. Also adds tests for the
said function.

pkg/utils/utils_suite_test.go

@@ -0,0 +1,13 @@
+package utils_test
+
+import (
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	"testing"
+)
+
+func TestUtils(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Utils Suite")
+}