CSVY Parsers Should Be Incorporated to Model Readers

[marxwillia]

Currently, the CSVY parser functions are located with the parsers in tardis/io/parsers, but those functions belong in the tardis/io/model_reader.py file. Please move all CSVY related parser functions to the model reader file. Note that this will cause import statements to break and some tests to fail, so these things need to be fixed as well.

[jayantbhakar]

is this issue still open or is it resolved?

[Jay-sanjay]

@jayantbhakar Is the Issue resolved, I can work on it