Merge pull request #9909 from nextcloud/feature/2192/allow_group_share_undeletion

apps/federatedfilesharing/lib/FederatedShareProvider.php

apps/files/css/files.scss

apps/files/img/unshare.svg

apps/files/tests/Controller/ViewControllerTest.php

apps/files_sharing/appinfo/app.php

apps/files_sharing/appinfo/routes.php

apps/files_sharing/composer/composer/autoload_classmap.php

apps/files_sharing/composer/composer/autoload_static.php

apps/files_sharing/js/app.js

apps/files_sharing/js/share.js

apps/files_sharing/js/sharedfilelist.js

...iles_sharing/lib/Controller/DeletedShareAPIController.php

apps/files_sharing/lib/Controller/ShareAPIController.php

apps/sharebymail/lib/ShareByMailProvider.php

lib/private/Share20/DefaultShareProvider.php

lib/private/Share20/Manager.php

lib/public/Share/IManager.php

lib/public/Share/IShareProvider.php