Loguru logging standardization for LLM Compressor

[markurtz]

Enable logging across LLM compressor and enable environment configuration overrides for library imports

SUMMARY:

• Added LogerConfig and refactored logging implementation to enable environment and configuration overrides for libraries that import LLM compressor.
• Enhanced docstrings and comments for clarity for logging implementations
• Refactored across the repo to remove _LOGGER and logging imports to move into loguru pathways.
• Added unit tests for logger functionality.

TEST PLAN:
Automation tests added, needs further manual testing for verfiication

[mgoin]

Is loguru a lightweight dep?

I ask because vLLM does all their logging through the native python library, so I think it would be nice to match up: https://github.com/vllm-project/vllm/blob/b90d8cd832669b9ad7c48cd9a431e80836778b56/vllm/logger.py

However if there is engineering value in a new logging library I can see the value, especially since it seems to preserve the same interface for creating new logs.

[Satrat]

@markurtz Got the tests in a passing state. Ran some manual tests of oneshot and reloading, the logs look good in both. Just had a few notes for you above