Refactor constants structure: separate public kwargs from internal options

- Create new CommonOptions class for internal option names
- Update Kwargs class to use public-facing kwarg names
- Update _COMMON_OPTIONS to map Kwargs to CommonOptions
- Update GetHeaders and internal functions to use CommonOptions
- Replace hardcoded kwargs strings in public APIs with Constants.Kwargs
- Update container.py, database.py, cosmos_client.py, _cosmos_client_connection.py

Co-authored-by: bambriz <[email protected]>

Author: Copilot