Add method to split range into smaller ranges of certain size #65
Description
For example:
import { IPv6CidrRange, IPv6Prefix } from 'ip-num';
const range = IPv6CidrRange.fromCidr('2001:db8::/29');
const prefix = new IPv6Prefix(32);
range.split(prefix);would yield (in CIDR format):
const result = [
'2001:db8::/32',
'2001:db9::/32',
'2001:dba::/32',
'2001:dbb::/32',
'2001:dbc::/32',
'2001:dbd::/32',
'2001:dbe::/32',
'2001:dbf::/32',
];