Modify Credentials & Connectivity Test to Use ICMP (PING) vs. NMAP

The Credentials & Connectivity Test uses NMAP to test availability. Netreo relies on ICMP to determine Host availability. This would be the preferred method to test connectivity/availability. Selecting the ICMP (PING) protocol in the GUI see Fig_1_CCT currently yields the results of an nmap scan. See Fig_2_CCT. NMAP provides a "false positive" that an ICMP query does not. The device dashboard Reports:Ping utility provides an ICMP query as a workaround. However this utility sources the ICMP query from the assigned Service Engine. It's not possible to source the ICMP query from multiple Service Engines as it is in the C&CT. Beneficial for troubleshooting connectivity between the devices and Service Engines. This would be extremely beneficial in any installation with >1 Service Engine per Instance.