merge file activity settings into a single 'favorite changed' item

apps/files/appinfo/info.xml

apps/files/composer/composer/autoload_classmap.php

apps/files/composer/composer/autoload_static.php

apps/files/lib/Activity/Settings/FileChanged.php

apps/files/lib/Activity/Settings/FileDeleted.php

apps/files/lib/Activity/Settings/FileFavorite.php

apps/files/lib/Activity/Settings/FileFavoriteChanged.php

apps/files/lib/Activity/Settings/FileRestored.php

apps/files/tests/Activity/Setting/GenericTest.php

apps/files_sharing/lib/Activity/Settings/PublicLinks.php

apps/files_sharing/lib/Activity/Settings/RemoteShare.php

apps/files_sharing/lib/Activity/Settings/Shared.php

lib/private/Tags.php