fix: add try-except error handling for AWQ module imports to provide …

[Priyanshjain10]

…better error messaging

Fixes #42141

When loading models with AWQ quantization, users encountered unclear ModuleNotFoundError when the awq package structure didn't match expectations.

This fix wraps the awq module imports in try-except blocks and provides:

• Clear error messages when imports fail
• Information about which version/variant failed
• Helpful installation instructions pointing to the llm-awq repository

The error handling catches ImportError, ModuleNotFoundError, and AttributeError to handle various failure modes:

• Corrupted or incomplete awq installations
• Version mismatches between autoawq and transformers
• Missing or incompatible submodules

With these changes, users will receive helpful diagnostic information instead of cryptic import errors.

What does this PR do?

Fixes # (issue)

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