DRILL-6705: Fix various failures in Crypto / Network / Phonetic functions when invalid input is given
1. aes_decrypt / aes_ecrypt - moved cyper init part into eval method since it not a constant and can be different for each input
2. double_metaphone - fixed NPE when given string is empty
3. in_network / address_count / broadcast_address / netmask / low_address / high_address / - fixed IllegalArgumentException in case of invalid input
4. is_private_ip / inet_aton - fixed ArrayIndexOutOfBoundsException / NumberFormatException in case of invalid input
5. is_valid_IP / is_valid_IPv4 / is_valid_IPv6 - removed unnecessary checks
6. Added appropriate unit tests
closes #1443
