Add webwall function to add/remove ICMP timestamp request and reply DENY/PERMIT rule

------------------------- add permit icmp timestamp request/reply rule -------------------------
array@RADUISServerHank:~$ sudo hping3 -1 --icmptype 13 192.168.100.168

HPING 192.168.100.168 (ens34 192.168.100.168): icmp mode set, 28 headers + 0 data bytes

len=46 ip=192.168.100.168 ttl=64 id=60880 icmp_seq=0 rtt=3.9 ms

ICMP timestamp: Originate=8867553 Receive=8865915 Transmit=8865915

ICMP timestamp RTT tsrtt=4
len=46 ip=192.168.100.168 ttl=64 id=60885 icmp_seq=1 rtt=3.8 ms

ICMP timestamp: Originate=8868553 Receive=8866915 Transmit=8866915

ICMP timestamp RTT tsrtt=4
len=46 ip=192.168.100.168 ttl=64 id=60896 icmp_seq=2 rtt=11.7 ms

ICMP timestamp: Originate=8869553 Receive=8867915 Transmit=8867915

ICMP timestamp RTT tsrtt=12
^C

--- 192.168.100.168 hping statistic ---

3 packets transmitted, 3 packets received, 0% packet loss

round-trip min/avg/max = 3.8/6.5/11.7 ms

----------------------- remove permit icmp timestamp request/reply rule -----------------------
array@RADUISServerHank:~$ sudo hping3 -1 --icmptype 13 192.168.100.168

HPING 192.168.100.168 (ens34 192.168.100.168): icmp mode set, 28 headers + 0 data bytes

^C

--- 192.168.100.168 hping statistic ---

290 packets transmitted, 0 packets received, 100% packet loss

round-trip min/avg/max = 0.0/0.0/0.0 ms