Add generic-mode URL validation and UI

Introduce a "generic_mode" option to allow validating/downloading from non-YouTube sites and wire it through the UI, config, and validation logic. Key changes:

- Add generic_mode default to ConfigManager and persist setting from DownloadSettingsDialog (checkbox + help text).
- Extend validate_video_url to accept a generic_mode flag and allow any http/https URL with a domain when enabled; pass this flag from Analysis and Download flows.
- Update YTSageApp to load/save generic_mode, update URL placeholder and settings tooltip behavior, and refresh tooltip when settings change.
- Improve robustness in FormatTableMixin: handle None/incorrect types for format_note, abr, resolution, ext, and codec values to avoid type errors and ensure consistent display.
- Add localization entries for generic mode, placeholder, and related help text across multiple language files and update the in-app default localization strings.

These changes enable broader site support via yt-dlp while hardening UI format handling and keeping user settings persistent.

ytsage/gui/ytsage_gui_analysis.py

@@ -287,7 +287,7 @@ class AnalysisMixin:
             return
         
         # Validate URL before processing
-        is_valid, error_message = validate_video_url(url)
+        is_valid, error_message = validate_video_url(url, generic_mode=self.generic_mode_enabled)
         if not is_valid:
             QMessageBox.warning(self, _("main_ui.error_title"), error_message)
             if hasattr(self, "animate_widget_shake"):