This commit moves the BaseLLM abstract base class from llm.py to a new file llms/base_llm.py to improve code organization. The changes include:
- Creating a new file src/crewai/llms/base_llm.py
- Moving the BaseLLM class to the new file
- Updating imports in __init__.py and llm.py to reflect the new location
- Updating test cases to use the new import path
The refactoring maintains the existing functionality while improving the project's module structure.
