Add skins "aventure", "nature" and "items"

fastlane/metadata/android/en-US/changelogs/32.txt

fastlane/metadata/android/fr-FR/changelogs/32.txt

lib/common/ui/parameters/parameter_widget.dart

lib/config/default_global_settings.dart

pubspec.yaml

resources/ui/skins/aventure/1.png

resources/ui/skins/aventure/2.png

resources/ui/skins/aventure/3.png

resources/ui/skins/aventure/4.png

resources/ui/skins/aventure/5.png

resources/ui/skins/aventure/6.png

resources/ui/skins/aventure/7.png

resources/ui/skins/aventure/8.png

resources/ui/skins/aventure/found.png

resources/ui/skins/aventure/unknown.png

resources/ui/skins/items/1.png

resources/ui/skins/items/2.png

resources/ui/skins/items/3.png

resources/ui/skins/items/4.png

resources/ui/skins/items/5.png