Fix problems with DataFrame WriteCsv

[dakersnar]

#5647 is no longer present, but while investigating that issue I discovered some bugs with WriteCsv. This PR does the following:

• Fixes bugs where text qualifiers (quotation marks) were not properly added to the CSV output by WriteCsv in the following cases:
  • There are separators in a row entry
  • There are separators in a header name
  • There are newlines in a row entry
  • There are newlines in a header name
• Adds test cases both confirming [DataFrame] can't handle separators in data #5647 is solved and validating that the above bugs are fixed.

This is my first contribution to this repo so style criticism appreciated.

[codecov]

Codecov Report

Merging #6303 (fe0adcd) into main (f117cd8) will increase coverage by 0.24%.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6303      +/-   ##
==========================================
+ Coverage   68.39%   68.63%   +0.24%     
==========================================
  Files        1144     1171      +27     
  Lines      244991   247916    +2925     
  Branches    25411    25742     +331     
==========================================
+ Hits       167558   170157    +2599     
- Misses      70775    71015     +240     
- Partials     6658     6744      +86     

Flag	Coverage Δ
Debug	68.63% <100.00%> (+0.24%)	⬆️
production	63.04% <100.00%> (+0.20%)	⬆️
test	89.09% <100.00%> (+0.10%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/Microsoft.Data.Analysis/DataFrame.IO.cs	81.15% <100.00%> (+1.92%)	⬆️
...Microsoft.Data.Analysis.Tests/DataFrame.IOTests.cs	98.80% <100.00%> (+0.22%)	⬆️
...Microsoft.ML.TorchSharp/Utils/DefaultDictionary.cs	0.00% <0.00%> (-30.62%)	⬇️
...luators/Metrics/MulticlassClassificationMetrics.cs	89.47% <0.00%> (-10.53%)	⬇️
...Microsoft.ML.AutoML.Tests/AutoMLExperimentTests.cs	92.38% <0.00%> (-7.62%)	⬇️
test/Microsoft.ML.Tests/TextClassificationTests.cs	93.75% <0.00%> (-6.25%)	⬇️
test/Microsoft.ML.AutoML.Tests/AutoFitTests.cs	79.56% <0.00%> (-6.19%)	⬇️
src/Microsoft.ML.Maml/MAML.cs	24.36% <0.00%> (-2.54%)	⬇️
...eColumn.BinaryOperationImplementations.Exploded.cs	47.65% <0.00%> (-1.38%)	⬇️
test/Microsoft.ML.AutoML.Tests/DatasetUtil.cs	97.84% <0.00%> (-1.15%)	⬇️
... and 80 more

[dakersnar]

@eerhardt Thanks for the feedback. Everything should be addressed now.

[eerhardt]

LGTM! Thanks.