Hide delegates, model parameters constructors and other small things

[Ivanidzo4ka]

should fix #1974

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (master@b604b07). Click here to learn what that means.
The diff coverage is 100%.

@@            Coverage Diff            @@
##             master    #2701   +/-   ##
=========================================
  Coverage          ?   71.59%           
=========================================
  Files             ?      805           
  Lines             ?   141996           
  Branches          ?    16119           
=========================================
  Hits              ?   101655           
  Misses            ?    35905           
  Partials          ?     4436

Flag	Coverage Δ
#Debug	71.59% <100%> (?)
#production	67.88% <100%> (?)
#test	85.73% <ø> (?)

Impacted Files	Coverage Δ
...e/FieldAwareFactorizationMachineModelParameters.cs	74.7% <ø> (ø)
src/Microsoft.ML.FastTree/GamClassification.cs	89% <ø> (ø)
...StandardLearners/Standard/LinearModelParameters.cs	60.63% <ø> (ø)
...Standard/MultiClass/MultiClassNaiveBayesTrainer.cs	87.8% <ø> (ø)
src/Microsoft.ML.PCA/PcaTrainer.cs	79.64% <ø> (ø)
...t.ML.Data/Transforms/ValueToKeyMappingEstimator.cs	87.03% <ø> (ø)
...osoft.ML.StaticPipe/CategoricalStaticExtensions.cs	83.01% <ø> (ø)
...Microsoft.ML.Data/DataLoadSave/TransformWrapper.cs	33% <ø> (ø)
src/Microsoft.ML.FastTree/GamRegression.cs	89.09% <ø> (ø)
...LogisticRegression/MulticlassLogisticRegression.cs	67.46% <ø> (ø)
... and 1 more

[artidoro]

public sealed class TransformWrapper : ITransformer

I can't wait for this to go away! #Resolved

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Refers to: src/Microsoft.ML.Data/DataLoadSave/TransformWrapper.cs:20 in 622543c. [](commit_id = 622543c, deletion_comment = False)

[artidoro]

        public readonly bool TextKeyValues;

You used to add doc comments in your previous PRs :`(

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Refers to: src/Microsoft.ML.Data/Transforms/ValueToKeyMappingEstimator.cs:42 in 622543c. [](commit_id = 622543c, deletion_comment = False)

[Ivanidzo4ka]

public sealed class TransformWrapper : ITransformer

All we need to do is untangle that mess in word bag extraction.

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In reply to: 466601135 [](ancestors = 466601135)

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Refers to: src/Microsoft.ML.Data/DataLoadSave/TransformWrapper.cs:20 in 622543c. [](commit_id = 622543c, deletion_comment = False)

[Ivanidzo4ka]

        public readonly bool TextKeyValues;

Purpose of this PR is to hide stuff.
More we hide, less to document :D

I do want to change all this Term, MaxNumKeys property to something more appropriate, but not in this PR.

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In reply to: 466601428 [](ancestors = 466601428)

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Refers to: src/Microsoft.ML.Data/Transforms/ValueToKeyMappingEstimator.cs:42 in 622543c. [](commit_id = 622543c, deletion_comment = False)

[abgoswam]

TrivialWrapperEstimator [](start = 26, length = 23)

where did this go ? #Resolved

[abgoswam]

ah i see. no usages in code :)

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In reply to: 259595477 [](ancestors = 259595477)

[Ivanidzo4ka]

To Valhalla!

[abgoswam]