Support Dart only

[iapicca]

DESCRIPTION

it would be great to be able to use this package in backend,
but at the time of writing rHTTP depends on flutter
so it can't be used

as far as I know flutter_rust_bridge is "flutter" only by name
and can be used in pure dart implementation

PROPOSAL

support the creation of dart server based on rHTTP by provide a "pure dart" implementation

[Tienisto]

Yes, it seems to be possible according to https://cjycode.com/flutter_rust_bridge/guides/miscellaneous/pure-dart

I am wondering if it still works on Flutter because flutter/flutter#129757 is not resolved and dart-lang/sdk#50565 is only available via experimental flag.

If we are lucky, then adding a build.dart file (https://github.com/fzyzcjy/flutter_rust_bridge/blob/master/frb_example/pure_dart/build.dart) is enough to enable experimental Dart support while still maintaining existing Flutter support.

[Tienisto]

I tried to add build.dart into the project but flutter_rust_bridge_utils is not published on pub.dev yet.

Ref: fzyzcjy/flutter_rust_bridge#2274