Change net.if.discovery and add new keys

Add {#IFALIAS} and {#IFTYPE} in net.if.discovery. Add net.if.type["{#IFGUID}"], net.if.status["{#IFGUID}"], net.if.speed["{#IFGUID}"] as new keys in order to remove WMI request from "Windows network by Zabbix agent" template. Add net.if.type["{#IFNAME}"], net.if.status["{#IFNAME}"], net.if.speed["{#IFNAME}"] as new keys in order to remove vfs.file.contents from "Linux network interfaces by Zabbix agent" template.