a bunch of minor changes combined:

- From instead of Into
- unsafe_data_ref for other payloads
- CByteSlice for returning memory spans
- send Packet instead of Into<Packet>
- expose packet layer to C/C#

examples/lang_cs/Program.cs

@@ -2,8 +2,8 @@
 
 using var connection = Connection.Open("127.0.0.1:2342");
 
-connection.Send(Command.Clear());
-connection.Send(Command.Brightness(128));
+connection.Send(Command.Clear().IntoPacket());
+connection.Send(Command.Brightness(128).IntoPacket());
 
 using var pixels = PixelGrid.New(Constants.PixelWidth, Constants.PixelHeight);
 
@@ -14,6 +14,6 @@ for (var offset = 0; offset < int.MaxValue; offset++)
     for (var y = 0; y < pixels.Height; y++)
         pixels[(y + offset) % Constants.PixelWidth, y] = true;
 
-    connection.Send(Command.BitmapLinearWin(0, 0, pixels.Clone()));
+    connection.Send(Command.BitmapLinearWin(0, 0, pixels.Clone()).IntoPacket());
     Thread.Sleep(14);
 }