Add generic IP utilities (#3038)

* Add generic IP calculations

Add:
calculateNetworkID(IPAddress ip, IPAddress subnet) => Calculate the network id using the ip and subnet (e.g. 192.168.0.0)
calculateBroadcast(IPAddress ip, IPAddress subnet) => Calculate the broadcast ip using the ip and subnet (e.g. 192.168.0.255)
calculateSubnetCIDR(IPAddress subnetMask) => Calculate the subnet CIDR using the subnet (e.g. 24)

Add:
broadcastIP() => Retrieve the network id (e.g. 192.168.0.0)
networkID() => Retrieve the broadcast IP (e.g. 192.168.0.255)
subnetCIDR() => Retrieve the subnet CIDR (e.g. 24)

Add:
broadcastIP() => Retrieve the network id (e.g. 192.168.0.0)
networkID() => Retrieve the broadcast IP (e.g. 192.168.0.255)
subnetCIDR() => Retrieve the subnet CIDR (e.g. 24)

Add:
softAPBroadcastIP() => Retrieve the network id (e.g. 192.168.0.0)
softAPNetwrokID() => Retrieve the broadcast IP (e.g. 192.168.0.255)
softAPSubnetCIDR() => Retrieve the subnet CIDR (e.g. 24)

libraries/WiFi/src/WiFiAP.h

@@ -45,6 +45,10 @@ public:
 
     IPAddress softAPIP();
 
+    IPAddress softAPBroadcastIP();
+    IPAddress softAPNetworkID();
+    uint8_t softAPSubnetCIDR();
+
     bool softAPenableIpV6();
     IPv6Address softAPIPv6();