Fix bugs & support .tgs & .lottie

[xvrh]

• Fixed varying opacity stops across keyframes in the same gradient
• Fixed rounded corners for non-closed curves
• Allow to load Telegram Stickers (.tgs)

Lottie.asset(
  'sticker.tgs',
  decoder: LottieComposition.decodeGZip,
)

• Expose a hook to customize how to decode zip archives. This is useful for dotlottie (.lottie) archives when we want to specify a specific .json file inside the archive

Lottie.asset(
  'animation.lottie',
  decoder: customDecoder,
);

Future<LottieComposition?> customDecoder(List<int> bytes) {
  return LottieComposition.decodeZip(bytes, filePicker: (files) {
    return files.firstWhere((f) => f.name == 'animations/cat.json');
  });
}

• Remove name property from LottieComposition
• imageProviderFactory is not used in .zip file by default anymore. To restore the old behaviour, use:

  
  Future<LottieComposition?> decoder(List<int> bytes) {
  return LottieComposition.decodeZip(bytes, imageProviderFactory: imageProviderFactory);
  }

Lottie.asset('anim.json', imageProviderFactory: imageProviderFactory, decoder: decoder)