refactor: Apply PEP8 naming conventions - convert PascalCase methods to snake_case

This comprehensive refactoring applies PEP8 naming conventions across the codebase:

## Core Changes:

### src/cli/Main.py
- Renamed __InitList__() to __init_list__()
- Renamed print_Download_Progress() to print_download_progress()
- Fixed variable naming: task3 -> download_progress_task
- Fixed parameter spacing: words :str -> words: str
- Updated all method calls to use snake_case
- Added comprehensive docstrings

### src/core/SerieScanner.py
- Renamed Scan() to scan()
- Renamed GetTotalToScan() to get_total_to_scan()
- Renamed Reinit() to reinit()
- Renamed private methods to snake_case:
  - __ReadDataFromFile() -> __read_data_from_file()
  - __GetMissingEpisodesAndSeason() -> __get_missing_episodes_and_season()
  - __GetEpisodeAndSeason() -> __get_episode_and_season()
  - __GetEpisodesAndSeasons() -> __get_episodes_and_seasons()
- Added comprehensive docstrings to all methods
- Fixed long line issues

### src/core/providers/base_provider.py
- Refactored abstract base class with proper naming:
  - Search() -> search()
  - IsLanguage() -> is_language()
  - Download() -> download()
  - GetSiteKey() -> get_site_key()
  - GetTitle() -> get_title()
- Added proper type hints (Dict, List, etc.)
- Added comprehensive docstrings explaining contracts
- Fixed newline at end of file

### src/core/providers/aniworld_provider.py
- Renamed public methods to snake_case:
  - Search() -> search()
  - IsLanguage() -> is_language()
  - Download() -> download()
  - GetSiteKey() -> get_site_key()
  - GetTitle() -> get_title()
  - ClearCache() -> clear_cache()
  - RemoveFromCache() -> remove_from_cache()
- Renamed private methods to snake_case:
  - _GetLanguageKey() -> _get_language_key()
  - _GetKeyHTML() -> _get_key_html()
  - _GetEpisodeHTML() -> _get_episode_html()
- Fixed import organization
- Improved code formatting and line lengths
- Added docstrings to all methods

### src/core/SeriesApp.py
- Updated all calls to use new snake_case method names
- Updated loader calls: loader.Search() -> loader.search()
- Updated loader calls: loader.Download() -> loader.download()
- Updated scanner calls: SerieScanner.GetTotalToScan() -> SerieScanner.get_total_to_scan()
- Updated scanner calls: SerieScanner.Reinit() -> SerieScanner.reinit()
- Updated scanner calls: SerieScanner.Scan() -> SerieScanner.scan()

### tests/unit/test_series_app.py
- Updated mock calls to use new snake_case method names:
  - get_total_to_scan() instead of GetTotalToScan()
  - reinit() instead of Reinit()
  - scan() instead of Scan()

## Verification:
- All unit tests pass ✅
- All integration tests pass ✅
- All tests pass ✅
- No breaking changes to functionality

## Standards Applied:
- PEP 8: Function/method names use lowercase with underscores (snake_case)
- PEP 257: Added comprehensive docstrings
- Type hints: Proper type annotations where applicable
- Code formatting: Fixed line lengths and spacing

src/core/providers/base_provider.py

@@ -1,27 +1,94 @@
 from abc import ABC, abstractmethod
+from typing import Dict, List
 
 
 class Loader(ABC):
+    """Abstract base class for anime data loaders/providers."""
+
     @abstractmethod
-    def Search(self, word: str) -> list:
+    def search(self, word: str) -> List[Dict]:
+        """Search for anime series by name.
+        
+        Args:
+            word: Search term
+            
+        Returns:
+            List of found series as dictionaries
+        """
         pass
 
     @abstractmethod
-    def IsLanguage(self, season: int, episode: int, key: str, language: str = "German Dub") -> bool:
+    def is_language(
+        self,
+        season: int,
+        episode: int,
+        key: str,
+        language: str = "German Dub"
+    ) -> bool:
+        """Check if episode exists in specified language.
+        
+        Args:
+            season: Season number
+            episode: Episode number
+            key: Series key
+            language: Language to check (default: German Dub)
+            
+        Returns:
+            True if episode exists in specified language
+        """
         pass
 
     @abstractmethod
-    def Download(self, baseDirectory: str, serieFolder: str, season: int, episode: int, key: str, progress_callback: callable = None) -> bool:
+    def download(
+        self,
+        base_directory: str,
+        serie_folder: str,
+        season: int,
+        episode: int,
+        key: str,
+        progress_callback=None
+    ) -> bool:
+        """Download episode to specified directory.
+        
+        Args:
+            base_directory: Base directory for downloads
+            serie_folder: Series folder name
+            season: Season number
+            episode: Episode number
+            key: Series key
+            progress_callback: Optional callback for progress updates
+            
+        Returns:
+            True if download successful
+        """
         pass
 
     @abstractmethod
-    def GetSiteKey(self) -> str:
+    def get_site_key(self) -> str:
+        """Get the site key/identifier for this provider.
+        
+        Returns:
+            Site key string (e.g., 'aniworld.to')
+        """
         pass
 
     @abstractmethod
-    def GetTitle(self) -> str:
+    def get_title(self) -> str:
+        """Get the human-readable title of this provider.
+        
+        Returns:
+            Provider title string
+        """
         pass
 
     @abstractmethod
-    def get_season_episode_count(self, slug: str) -> dict:
-        pass
+    def get_season_episode_count(self, slug: str) -> Dict[int, int]:
+        """Get season and episode counts for a series.
+        
+        Args:
+            slug: Series slug/key
+            
+        Returns:
+            Dictionary mapping season number to episode count
+        """
+        pass