Remove QuantizationConfig fields patch from NodeActivationQuantizationConfig

[irenaby]

Pull Request Description:

Remove the intermediate patch that injected fields from QuantizationConfig back to NodeActivationQuantizationConfig.
Use QuantizationConfig directly in all places that read it from the node candidates.
Remove min_threshold from TrainableQuantizerActivationConfig.

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).

[yarden-yagil-sony]

Approved with 2 minor comments