Add options to manage output as array of dictionaries

I find quite usefull to use the first line of a CSV as key columns for the rest of the document.
I added an options flag (CHCSVParserOptionsFirstLineAsKeys) to make that.
The result is an array of dictionaries starting from index 1 instead of an array of arrays starting form index 0.
I also added a unit test to handle the case. There are other 3 tests that fail, but they do so on Master branch as well.