Add an option to dynamically disable configurable quantizers, separate configuration api for activation and weights quantizers

[irenaby]

Pull Request Description:

• When setting bitwidth to configurable quantizer, None can now be passed to disable quantization.
• Setting bitwidth api was split to separate apis for activation and weights
• Remove SensotivityEvaluation factory from fw_impl, keep only the relevant quant classes.

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).

[reuvenperetz]

Is this supposed to be numpy? Why not tf tensor?

[irenaby]

I think the actual quantization methods use numpy. But I just complied with the existing interface, it's even has numpy as a return type hint.