new & opt

new: support set maxRetryCount of server reconnection
opt: server detail UI
opt: server provider
opt: `ssh` page on Android

lib/view/page/sftp/view.dart

@@ -177,7 +177,7 @@ class _SFTPPageState extends State<SFTPPage> {
       );
 
   Widget _buildFileView() {
-    if (_client == null || _si?.cs != ServerConnectionState.connected) {
+    if (_client == null || _si?.cs != ServerState.connected) {
       return centerCircleLoading;
     }