Fix more missing or broken PHPDoc

apps/files_encryption/hooks/hooks.php

apps/files_encryption/lib/proxy.php

apps/files_external/lib/config.php

apps/files_external/lib/ftp.php

apps/files_external/lib/smb.php

apps/files_sharing/lib/cache.php

apps/files_sharing/lib/maintainer.php

apps/files_sharing/lib/sharedstorage.php

apps/files_trashbin/lib/hooks.php

apps/files_versions/lib/hooks.php