fix(dotnet): support IP address server names

Author: CBenoit

ffi/dotnet/Devolutions.IronRdp/src/Connection.cs

@@ -197,8 +197,15 @@ static async Task SingleConnectStep<T>(ClientConnector connector, WriteBuf buf,
 
     static async Task<NetworkStream> CreateTcpConnection(String servername, int port)
     {
-        IPHostEntry ipHostInfo = await Dns.GetHostEntryAsync(servername);
-        IPAddress ipAddress = ipHostInfo.AddressList[0];
+        IPAddress ipAddress;
+
+        try {
+            ipAddress = IPAddress.Parse(servername);
+        } catch (FormatException) {
+            IPHostEntry ipHostInfo = await Dns.GetHostEntryAsync(servername);
+            ipAddress = ipHostInfo.AddressList[0];
+        }
+
         IPEndPoint ipEndPoint = new(ipAddress, port);
 
         TcpClient client = new TcpClient();
@@ -220,4 +227,4 @@ public static byte[] Vecu8ToByte(VecU8 vecU8)
         vecU8.Fill(buffer);
         return buffer;
     }
-}
+}