Add functionality to FusingInfo class to preserve quantization config

[kkawa14]

Pull Request Description:

Add functionality to the FusingInfo class to preserving fusion quantization configs.
Add functionality to the FQC to get fusion quantization config from the Fusing class.
Add unittests for the Fusing class.

Checklist before requesting a review:

• I set the appropriate labels on the pull request.
• I have added/updated the release note draft (if necessary).
• I have updated the documentation to reflect my changes (if necessary).
• All function and files are well documented.
• All function and classes have type hints.
• There is a licenses in all file.
• The function and variable names are informative.
• I have checked for code duplications.
• I have added new unittest (if necessary).