wasm fixes

veilid-flutter/lib/veilid_stub.dart

@@ -1,3 +1,9 @@
+import 'dart:typed_data';
+
 import 'veilid.dart';
 
 Veilid getVeilid() => throw UnsupportedError('Cannot create Veilid object');
+Uint8List convertUint8ListFromJson(dynamic json) =>
+    throw UnsupportedError('Cannot convertUint8ListFromJson');
+dynamic convertUint8ListToJson(Uint8List data) =>
+    throw UnsupportedError('Cannot convertUint8ListToJson');