WebUrlService not compatible with Flutter Web apps deployed outside of root path

[camrongiuliani]

https://github.com/Flutterando/modular/blob/edc191975f51416ba52ffb6f078125dedae15f0c/flutter_modular/lib/src/presenter/navigation/modular_route_information_parser.dart#L55C5-L55C63

When a Flutter Web app is deployed somewhere other than the root of the server, for example:
https://www.example.com/flutterapps/myapp

Modular redirects to:
https://www.example.com/flutterapps/myapp/#/flutterapps/myapp/

Due to the UrlService being favored over the user defined initial route, there is no clean way to solve for this.

The only way I could find to remedy this is to use a redirect route, but this is less than ideal when the deployment path differs for multiple different clients.

When _firstParse is true, we likely need to prefer the user defined initial route, and if not specified, fallback on the UrlService.

Thoughts?

[camrongiuliani]

Opened a PR for the issue mentioned.