Allow convertion from Date and Timestamp Spark types to Date and DateTime TransmogrifAI types

[tovbinm]

Related issues
This bug was discovered and reported through Gitter by @msouder

Describe the proposed solution
Added specific cases for java.util.Date value conversions in FeatureTypeSparkConverter for Date and DateTime

Describe alternatives you've considered
N/A

[codecov]

Codecov Report

Merging #188 into master will increase coverage by 0.04%.
The diff coverage is 83.33%.

@@            Coverage Diff             @@
##           master     #188      +/-   ##
==========================================
+ Coverage   86.31%   86.35%   +0.04%     
==========================================
  Files         307      307              
  Lines        9971     9975       +4     
  Branches      336      551     +215     
==========================================
+ Hits         8606     8614       +8     
+ Misses       1365     1361       -4

Impacted Files	Coverage Δ
...com/salesforce/op/features/FeatureSparkTypes.scala	96.12% <100%> (ø)	⬆️
.../op/features/types/FeatureTypeSparkConverter.scala	98.19% <80%> (-0.87%)	⬇️
...es/src/main/scala/com/salesforce/op/OpParams.scala	89.79% <0%> (+4.08%)	⬆️
.../salesforce/op/features/FeatureBuilderMacros.scala	100% <0%> (+100%)	⬆️

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