Remove most of the iputils from tests

[Michal-Leszczynski]

So basically, SM handles IPV6 poorly, as in most places it stores IP addresses in string format and compares them as strings as well.
Since IPV6 does not have a unique string representation, it creates issues.

And what are we doing when a test fails beacuse of mismatch in IPV6 string representation?
We alter the test to use required representation instead of fixing SM implementation...

Functions like:

// ToCanonicalIP replaces ":0:0" in IPv6 addresses with "::"
// ToCanonicalIP("192.168.0.1") -> "192.168.0.1"
// ToCanonicalIP("100:200:0:0:0:0:0:1") -> "100:200::1".
func ToCanonicalIP(host string) string {
	val := net.ParseIP(host)
	if val == nil {
		return host
	}
	return val.String()
}

// ExpandIP expands IPv6 addresses "::" to ":0:0..."
// ToCanonicalIP("192.168.0.1") -> "192.168.0.1"
// ToCanonicalIP("100:200:0:0:0:0:0:1") -> "100:200::1".
func ExpandIP(host string) string {
	if !strings.Contains(host, "::") {
		return host
	}
	expected := 7
	existing := strings.Count(host, ":") - 1
	return strings.Replace(host, "::", strings.Repeat(":0", expected-existing)+":", 1)
}

Needs to be removed from our tests so that we are not hiding problems with IPV6 handling.
Obviously, SM implementation needs to be updated to handle those cases correctly.