Add the support for ignoreTrailingWhiteSpace and ignoreLeadingWhiteSpace

[HyukjinKwon]

https://github.com/databricks/spark-csv/issues/304

This PR adds the support for ignoreTrailingWhiteSpace and ignoreLeadingWhiteSpace options which were exposed but not implemented.

For Apache Common CSV Parser (common), it supports the functionalities only when both ignoreTrailingWhiteSpace and ignoreLeadingWhiteSpace are set to true by using withIgnoreSurroundingSpaces() at CSVFormat.

For Univocity parser (univocity), it supports this functionalities for ignoreTrailingWhiteSpace, and/or ignoreLeadingWhiteSpace by using setIgnoreLeadingWhitespaces() and/or setIgnoreTrailingWhitespaces() at CsvParserSettings.

[codecov-io]

Current coverage is 87.43%

Merging #306 into master will increase coverage by +0.77% as of 7eb2c30

@@ master #306 diff @@
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Files 12 12 Stmts 540 541 +1
Branches 160 160 Methods 0 0 ======================================
+ Hit 468 473 +5
Partial 0 0 + Missed 72 68 -4

Review entire Coverage Diff as of 7eb2c30

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[dbspace]

I try to use this, but I am facing a strange issue. I am able to create a dataframe from the csv, but if I try to use the dataframe that is created and convert 1 of column from string to date using withColumn and then try to write it out to parquet I get a number format exception. However if I write the dataframe out as parquet first and read the parquet back and use the withColumn to create a new dataframe and write that out everything works fine. I can create a test case if you need more information

[HyukjinKwon]

I can rebase this if it seems worth adding it.

[mrchristine]

Any reason users would want to keep whitespace on one side? I'd recommend simplifying this to add "ignoreHeaderWhitespace" to ignore trailing and leading whitespace. I don't see a use case where users would want to keep one or the other, and it makes referring to columns more complex. Users might run into more issues if they only add 1 option, but wanted both.

[HyukjinKwon]

Closing this as it is now maintenance mode and it seems it is not a critical bug.

[jarvisrjz]

Any plans to add this? I noticed the two ignore whitespace options on the javadoc but was unable to use them

[dereXeus]

I have forked this repo. Any chances you can raise a pull request to it ?