Remove dependency on csv package

[harendra-kumar]

csv is pretty simple. We can use something similar to https://github.com/composewell/streamly-examples/blob/master/examples/CSVParser.hs or just replace parsec with streamly parser in the csv package, it is trivial parsing. In fact, we can add a Streamly.CSV module in streamly itself, to load and dump the csv format.

[adithyaov]

See #32

[adithyaov]

We can just leave this be I believe. I do not want to depend on any internal modules of streamly, which I believe I'll need to depend on to make a clean solution.