opt.: migrate to new fl_lib (#649)

Fixes #648

lib/view/page/storage/local.dart

@@ -51,7 +51,7 @@ class _LocalFilePageState extends State<LocalFilePage>
   @override
   Widget build(BuildContext context) {
     super.build(context);
-    final title = _path.path.fileName ?? libL10n.file;
+    final title = _path.path.fileNameGetter ?? libL10n.file;
     return Scaffold(
       appBar: CustomAppBar(
         title: AnimatedSwitcher(

lib/view/page/storage/sftp.dart

@@ -591,7 +591,7 @@ class _SftpPageState extends State<SftpPage> with AfterLayoutMixin {
   String _getRemotePath(SftpName name) {
     final prePath = _status.path.path;
     // Only support Linux as remote now, so the seperator is '/'
-    return prePath.joinPath(name.filename, seperator: '/');
+    return prePath.joinPath(name.filename, separator: '/');
   }
 
   /// Local file dir + server id + remote path