Updated flutter platforms

[FaFre]

This PR adds Linux support and recreates android/ios structures, as well as the outdated metadata file.

[Mosc]

I don't have a Linux development machine to test this on, so I trust you that this is working well. :)

[FaFre]

@Mosc all done

[FaFre]

@Mosc I also got web working locally. It required some minor code changes. However, the HN login doesn't work since in the browser CORS comes into game. Shall I push this changes or are you planning to not support web anyways?

[Mosc]

@Mosc I also got web working locally. It required some minor code changes. However, the HN login doesn't work since in the browser CORS comes into game. Shall I push this changes or are you planning to not support web anyways?

Web support is not that different from Linux support in that respect: I'm not going to use it personally and I don't have plans to officially distribute it, but if others gain value from it I don't mind having it included in the repository. As long as the effect on the code is not too invasive you should feel free to push it.

It's interesting that you mention the login functionality not working, because isn't the same true for the Linux target? Or do you mean that it fails in a different way?

[Mosc]

In its current state I'd be happy to merge the PR, but let me know if you want to add web support first.

[FaFre]

I just pushed the web support. One small dependency is required, because dart:io is not available for web.

[Mosc]

I have some issues with universal_io being included for a single line of code. As I understand it the if (Platform.isAndroid) wouldn't work otherwise, right? How about changing that to if (!kIsWeb && defaultTargetPlatform == TargetPlatform.android)?

Please also add the following to flutter_launcher_icons.yaml to generate Glider favicons rather than the default Flutter one, and then run flutter pub run flutter_launcher_icons:

  web:
    generate: true

Unfortunately that tool doesn't support Linux yet! Exclude any icon changes for other platforms, those have been optimized for size.

[FaFre]

@Mosc I finally found some time to fix the open points :)

Linking the Linux related issue for future references: fluttercommunity/flutter_launcher_icons#529

[Mosc]

Apologies for the late reply. I think the PR mostly looks good, but the changes to the existing icons should be reverted. They're larger than the current icon file sizes.

Exclude any icon changes for other platforms, those have been optimized for size.