This PR expands on a previous PR, which stores as it deserializes a dap response, taking the filename from the DMR. IT stores the deserialized data as a NetCDF4 using the NetCDF4 python library. However, a missing detail was to enforce now adding a .nc4 suffix to the filename. This is what this PR (originally) did. It

In addition to the title, this Pull Request also

• enforces a stream+deserialized dap response is stored with a suffix .nc4, where the filename is extracted from the dmr.
• Closes rename csv handler as its name collides with csv imports when running processes in parallel #612
• Tests are added to demonstrate the new or fixed behavior, and all tests pass
  on a local environment.