Let NTP Server can be updated in CLI and WebUI

The Jira ticket is:

https://arraynetworks.atlassian.net/browse/TWSD-1082
Originally,

we don't support editing in NTP Server function.

After researching,

I found we can just remove original data then add new data for updating,

so I changed both CLI and WebUI part.
For CLI,

the function add_ntpsrv_conf will pass host already exist, so the chrony config file will only write the latest data for the host.

I modified the function, so I can return 1 or 0 for is the host already in the config file.

Then I can check it in the related function ui_ntpserver.

If the host is exist,

then I will call delete/reset of Chrony command if NTP service is on.
Besides,

I found the Auth key can be empty in WebUI before,

and it is different from CLI design.

I fixed it and you can see the attachment "Warning of empty key id" for reference.

I also apply range of key id in WebUI this time, you can see the attachment "Show range of key id" for reference.