Merge yaru.dart and yaru_icons.dart into this repository

[Feichtmeier]

As discussed on discord we want to merge yaru.dart theme and yaru_icons.dart into this repository to avoid the unnecessary maintenance overhead of managing those three depedencies, especially because yaru_widgets has deps to yaru.dart and yaru_icons.dart but also because all of the community and canonical apps use those three libs always together, and never alone.

The plan:

• copy the source code of the icons and the theme to the yaru_widgets.dart repo
• rename yaru.dart and yaru_icons.dart to xx_archive.dart and set them to the archive mode
• then rename yaru_widgets.dart in the repo and pubspec to yaru.dart
• Make the icon page work in the github pages web page build! #857
• make a new 4.0.0 release when everything really works
• Help the canonicals migrating their apps, as it is an easy yet big diff to make
  CC @d-loose @spydon

[spydon]

I can migrate the Canonical repos, as long as none of them are pinned on a previous version, which I know some have been previously.

[Feichtmeier]

Important

yaru.dart 4.0.0 is now released

Information for canonical flutter contributors on what to do:

• remove yaru_icons and yaru_widgets from pubspec
• replace all imports of yaru_icons.dart and yaru_widgets.dart with just yaru.dart
• in case you were using YaruAnimatedIcon somewhere, the api has changed:
  

Here is the diff of this in musicpod as an example:
https://github.com/ubuntu-flutter-community/musicpod/pull/542/files

Was really straight forward
CC @spydon @d-loose @robert-ancell @BLKKKBVSIK

[Feichtmeier]

@spydon I think we are done here, or?

[spydon]

@spydon I think we are done here, or?

Probably!