Better wasm support

[simolus3]

• As dart2wasm can't convert JS typed data instances into Dart instances without copying, we have to avoid dart:typed_data pretty much everywhere in code we intend to compile to WASM. This affects the VFS layer which is a breaking change.
• todo there will probably be more changes required.

[hnvn]

I've got this error when trying to run flutter build web --wasm:

../../../.pub-cache/hosted/pub.dev/sqlite3-2.4.6/lib/src/ffi/memory.dart:2:1: Error: 'dart:ffi' can't be imported when compiling to Wasm.
import 'dart:ffi';

[simolus3]

You're importing package:sqlite3/sqlite3.dart somewhere, which does not support being compiled to wasm. You need to use conditional imports to only import package:sqlite3/wasm.dart (or package:sqlite3/common.dart for platform-agnostic code) when you compile your app to the web. If you're using drift you can use this package which takes care of that for you.

[hnvn]

Thank you @simolus3 , I get it work now, it's because of using old implementation that import sqlite3_flutter_libs manually. I followed new setup docs to add dependencies for drift and drift_flutter.