Removing featurizers now in ML.Net

[michaelgsharp]

This PR depends on PR #5205. Once that is in all the featurizer functionality that belongs in ML.Net itself will have been added already. We can then remove these 3 standalone transformers as they are now duplicate functionality.

[codecov]

Codecov Report

Merging #5209 into master will increase coverage by 13.80%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           master    #5209       +/-   ##
===========================================
+ Coverage   73.51%   87.32%   +13.80%     
===========================================
  Files        1016      243      -773     
  Lines      189844    43242   -146602     
  Branches    20427     1861    -18566     
===========================================
- Hits       139573    37761   -101812     
+ Misses      44700     5142    -39558     
+ Partials     5571      339     -5232     

Flag	Coverage Δ
#Debug	87.32% <ø> (+13.80%)	⬆️
#production	?
#test	87.32% <ø> (-0.16%)	⬇️

Impacted Files	Coverage Δ
...t.ML.Core/ComponentModel/LoadableClassAttribute.cs
...soft.ML.Data/DataLoadSave/Text/TextLoaderParser.cs
src/Microsoft.ML.DataView/IDataView.cs
...rosoft.ML.Data/DataView/CompositeRowToRowMapper.cs
src/Microsoft.ML.ImageAnalytics/ImageLoader.cs
.../Microsoft.ML.Data/Transforms/ExtensionsCatalog.cs
.../SubModelSelector/BestDiverseSelectorMulticlass.cs
src/Microsoft.ML.Core/Data/ModelSaveContext.cs
...StandardTrainers/Standard/Online/AveragedLinear.cs
....ML.Transforms/Text/SentimentAnalyzingTransform.cs
... and 757 more

[codecov]

Codecov Report

Merging #5209 into master will decrease coverage by 0.10%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #5209      +/-   ##
==========================================
- Coverage   73.51%   73.41%   -0.11%     
==========================================
  Files        1016     1010       -6     
  Lines      189844   187617    -2227     
  Branches    20427    20232     -195     
==========================================
- Hits       139573   137737    -1836     
+ Misses      44700    44399     -301     
+ Partials     5571     5481      -90     

Flag	Coverage Δ
#Debug	73.41% <ø> (-0.11%)	⬇️
#production	69.24% <ø> (-0.09%)	⬇️
#test	87.32% <ø> (-0.16%)	⬇️

Impacted Files	Coverage Δ
src/Microsoft.ML.Featurizers/Common.cs	57.14% <0.00%> (-7.62%)	⬇️
....ML.AutoML/PipelineSuggesters/PipelineSuggester.cs	79.83% <0.00%> (-3.37%)	⬇️
...soft.ML.Transforms/Text/WordEmbeddingsExtractor.cs	85.74% <0.00%> (-1.14%)	⬇️
src/Microsoft.ML.Maml/MAML.cs	26.21% <0.00%> (+1.45%)	⬆️
...c/Microsoft.ML.FastTree/Utils/ThreadTaskManager.cs	100.00% <0.00%> (+20.51%)	⬆️

[harishsk]

I am approving this, but please merge this after #5205 is merged.