Add comprehensive tests for formatter classes, services, and utilities

- Introduced tests for various formatter classes including TextFormatter, DurationFormatter, SizeFormatter, DateFormatter, and more to ensure correct formatting behavior.
- Added tests for service classes such as FileTreeService, MetadataService, and RenameService, covering directory validation, metadata extraction, and file renaming functionalities.
- Implemented utility tests for LanguageCodeExtractor, PatternExtractor, and FrameClassMatcher to validate their extraction and matching capabilities.
- Updated test cases to use datasets for better maintainability and clarity.
- Enhanced error handling tests to ensure robustness against missing or invalid data.

renamer/constants/cyrillic_constants.py

@@ -0,0 +1,21 @@
+"""Cyrillic character normalization constants.
+
+This module contains mappings for normalizing Cyrillic characters to their
+English equivalents for parsing filenames.
+"""
+
+# Cyrillic to English character mappings
+# Used for normalizing Cyrillic characters that look like English letters
+CYRILLIC_TO_ENGLISH = {
+    'р': 'p',  # Cyrillic 'er' looks like Latin 'p'
+    'і': 'i',  # Cyrillic 'i' looks like Latin 'i'
+    'о': 'o',  # Cyrillic 'o' looks like Latin 'o'
+    'с': 'c',  # Cyrillic 'es' looks like Latin 'c'
+    'е': 'e',  # Cyrillic 'ie' looks like Latin 'e'
+    'а': 'a',  # Cyrillic 'a' looks like Latin 'a'
+    'т': 't',  # Cyrillic 'te' looks like Latin 't'
+    'у': 'y',  # Cyrillic 'u' looks like Latin 'y'
+    'к': 'k',  # Cyrillic 'ka' looks like Latin 'k'
+    'х': 'x',  # Cyrillic 'ha' looks like Latin 'x
+    # Add more mappings as needed
+}