Add default/advanced mode toggle and test coverage for EPG matching

Enhanced EPG matching UX by adding radio button toggle to more clearly define optional advanced options. Also added test coverage for stability.

Frontend Changes:
- Added radio button UI to EPGMatchModal for default/advanced mode selection
- Default mode: Uses built-in normalization
- Advanced mode: Shows TagsInput fields for custom prefixes/suffixes/strings
- Mode persists across sessions and settings are preserved when switching modes

Test Coverage:
- Created EPGMatchModal.test.jsx with test cases covering:
  - Component rendering and mode switching
  - Form submission and settings persistence
  - Error handling and UI text variations

- Added test cases to SettingsUtils.test.js for EPG mode handling:
  - epg_match_mode routing to epg_settings group
  - Settings creation and preservation

Since advanced settings are saved persistently but ignored when default settings are used, this adds an easy way in the future to add additional advanced settings to EPG matching like  region influence, match aggression, and match preview, since users can easily switch between modes.

core/models.py

@@ -233,6 +233,7 @@ class CoreSettings(models.Model):
     def get_epg_settings(cls):
         """Get all EPG-related settings."""
         return cls._get_group(EPG_SETTINGS_KEY, {
+            "epg_match_mode": "default",
             "epg_match_ignore_prefixes": [],
             "epg_match_ignore_suffixes": [],
             "epg_match_ignore_custom": [],