fix(pve): Fix connection issues and add more error handlings (#1081)

* feat(PVE): Added display of PVE connection loading steps

Added a detailed display of loading steps during the PVE connection process, including stages such as establishing an SSH tunnel, authentication, and data retrieval

Also optimized the sorting of PVE storage content and the logic for handling connection errors

* feat(pve): Added error handling and prompts for PVE two-factor authentication

Added error handling for PVE servers when two-factor authentication is enabled, along with relevant error types and localized prompts

* feat(PVE): Added support for PVE passwords during key-based authentication

- Added the `pvePwd` field to the `ServerCustom` model
- Added a PVE password input field to the edit page (displayed only during key-based authentication)
- Updated multilingual files to support PVE-related loading states and password prompts
- Optimized PVE connection logic to support password verification during key-based authentication

lib/generated/l10n/l10n_ko.dart

@@ -514,10 +514,33 @@ class AppLocalizationsKo extends AppLocalizations {
   String get pveLoginFailed =>
       '로그인에 실패했습니다. 서버 설정의 사용자 이름/비밀번호로 Linux PAM 인증을 할 수 없습니다.';
 
+  @override
+  String get pveOtpRequired =>
+      'Two-factor authentication is enabled on this PVE server. Please enter the OTP code.';
+
   @override
   String get pveVersionLow =>
       '이 기능은 현재 테스트 단계이며 PVE 8+에서만 테스트되었습니다. 주의하여 사용해 주세요.';
 
+  @override
+  String get pveLoadingForwarding => 'Establishing SSH tunnel...';
+
+  @override
+  String get pveLoadingLogin => 'Authenticating with PVE...';
+
+  @override
+  String get pveLoadingData => 'Fetching cluster data...';
+
+  @override
+  String get pveLoadingConnect => 'Connecting...';
+
+  @override
+  String get pvePassword => 'PVE Password';
+
+  @override
+  String get pvePasswordHint =>
+      'Required when using key-based SSH authentication';
+
   @override
   String get read => '읽기';