Reorganize browser strategy code into separate modules for better maintainability and separation of concerns. Improve Docker implementation with:
- Add Alpine and Debian-based Dockerfiles for better container options
- Enhance Docker registry to share configuration with BuiltinBrowserStrategy
- Add CPU and memory limits to container configuration
- Improve error handling and logging
- Update documentation and examples
BREAKING CHANGE: DockerConfig, DockerRegistry, and DockerUtils have been moved to new locations and their APIs have been updated.