please add windows support

[insinfo]

please add windows support, i am developing an app for ios, android and windows that depends on this.

[clragon]

You can add windows support yourself:

1. add the desktop sqflite to your pubspec
   sqflite_common_ffi: ^2.1.0
2. call this somewhere before runApp:

  if (Platform.isWindows || Platform.isLinux) {
    sqfliteFfiInit();
    databaseFactory = databaseFactoryFfi;
  }