Add a day/time heatmap

android/gradle.properties

assets/translations/en.json

assets/translations/fr.json

fastlane/metadata/android/en-US/changelogs/42.txt

fastlane/metadata/android/fr-FR/changelogs/42.txt

lib/cubit/data_heatmap_cubit.dart

lib/cubit/data_heatmap_state.dart

lib/main.dart

lib/models/heatmap.dart

lib/network/scrobbles.dart

lib/ui/screens/statistics.dart

lib/ui/widgets/cards/heatmap.dart

lib/ui/widgets/charts/heatmap.dart

pubspec.yaml