Clean FeatureContributionCalculation and PermutationFeatureImportance

[artidoro]

Fixes #2965.

In this PR:

1. I move and rename the extension MlContext.Model.Explainability.FeatureContributionCalculation to MlContext.Transforms.CalculateFeatureContribution.

2. I also remove the MlContext.Model.Explainability catalog.

3. Clean up the FeatureContributionCalculation extension

4. Clean up PFI extensions

[rogancarr]

Looking good! Just a few questions / comments. #Resolved

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (master@0831865). Click here to learn what that means.
The diff coverage is 96.49%.

@@            Coverage Diff            @@
##             master    #2966   +/-   ##
=========================================
  Coverage          ?   72.35%           
=========================================
  Files             ?      803           
  Lines             ?   143295           
  Branches          ?    16155           
=========================================
  Hits              ?   103682           
  Misses            ?    35189           
  Partials          ?     4424

Flag	Coverage Δ
#Debug	72.35% <96.49%> (?)
#production	68.07% <93.1%> (?)
#test	88.52% <100%> (?)

Impacted Files	Coverage Δ
.../Microsoft.ML.Data/Model/ModelOperationsCatalog.cs	97.27% <ø> (ø)
...ansforms/PermutationFeatureImportanceExtensions.cs	97.93% <100%> (ø)
...st/Microsoft.ML.Functional.Tests/Explainability.cs	100% <100%> (ø)
...rosoft.ML.Data/Transforms/ExplainabilityCatalog.cs	100% <100%> (ø)
...est/Microsoft.ML.Tests/FeatureContributionTests.cs	98.55% <100%> (ø)
...forms/FeatureContributionCalculationTransformer.cs	73.55% <81.81%> (ø)

[rogancarr]

[Ivanidzo4ka]