Added CSV tools source.

[StegmannJCSDA]

Description

This PR adds the source for a CSV data and I/O utility.

Issue(s) addressed

Resolves #265

Dependencies

N/A

Impact

Expected impact on downstream repositories:
N/A

Checklist

• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• I have run the unit tests before creating the PR

[StegmannJCSDA]

This PR is ready for review.

[chengdang]

Hi @StegmannJCSDA, this is cool! Is there any requirement on the CVS file format? Do you think it is a good idea to add an I/O unit test just to demonstrate how to use these modules?

[StegmannJCSDA]

Thank you @chengdang!

Is there any requirement on the CVS file format?

-> Right now the code doesn't read the CHAR header. But otherwise it is fairly general. I am still planning to add a header capability though.

Do you think it is a good idea to add an I/O unit test just to demonstrate how to use these modules?

-> Absolutely. I have a test here:
https://github.com/StegmannJCSDA/CSVTOOLS/blob/develop/test/test_readcsv.f90
I'm not sure where to put the test data in CRTMv3 though.

[chengdang]

I'm not sure where to put the test data in CRTMv3 though.

That's a good point. Almost all I/O unit tests are for coefficient LUTs, so part of fix folder.
@BenjaminTJohnson might have more suggestions