InetAddressUtils scoped ID support

This is a remaining piece of https://issues.apache.org/jira/browse/HTTPCORE-616

org.apache.hc.core5.net.InetAddressUtils: Parsing may fail when an IPv6 scope id might be provided.

The following should likely succeed, but currently does not:

@Test
public void testScopedIPv6Address() {
    Assert.assertTrue(InetAddressUtils.isIPv6Address("fe80::1ff:fe23:4567:890a"));
    Assert.assertTrue(InetAddressUtils.isIPv6Address("fe80::1ff:fe23:4567:890a%eth2"));
    Assert.assertTrue(InetAddressUtils.isIPv6Address("fe80::1ff:fe23:4567:890a%3"));
}

This feature will impact parsing as well as detection, because as I understand it fe80::1ff:fe23:4567:890a%eth2" is URI encoded as https://[fe80::1ff:fe23:4567:890a%25eth2]:443/ (note the % is percent-encoded to %25).

This is based on a quick look at the ipv6 wiki page, I need to read though the current RFC guidance to verify the data I've provided is accurate.