Releng 2 1 Standardize LAN net display

On the main firewall rules multi-rule display it shows "LAN net" "WAN net" etc. But on the edit screen it shows "LAN subnet" "WAN subnet" etc. Make the edit screen have the same text as the main screen - this has been a source of enough little questions/queries on the forum. If it is made consistent then new people will not need to ask about it.
The same for the various NAT rule edit screens also.
Ermal committed this to main a few days ago: https://github.com/pfsense/pfsense/pull/902
I think it would be useful to have this little GUI standardization in 2.1.1 also, so this is the pull request for that.