Add internationalization support and enhance language handling

- Introduced a new i18n module for managing translations and language normalization, supporting both Russian and English.
- Updated various handlers and services to utilize the new translation functions for user-facing messages, improving user experience based on language preferences.
- Enhanced error handling and response messages to be language-aware, ensuring appropriate feedback is provided to users in their preferred language.
- Added tests for the i18n module to validate language detection and translation functionality.
- Updated the example environment file to include a default language configuration.

duty_teller.egg-info/requires.txt

@@ -0,0 +1,13 @@
+python-telegram-bot[job-queue]<23.0,>=22.0
+python-dotenv<2.0,>=1.0
+fastapi<1.0,>=0.115
+uvicorn[standard]<1.0,>=0.32
+sqlalchemy<3.0,>=2.0
+alembic<2.0,>=1.14
+pydantic<3.0,>=2.0
+icalendar<6.0,>=5.0
+
+[dev]
+pytest<9.0,>=8.0
+pytest-asyncio<1.0,>=0.24
+httpx<1.0,>=0.27