Update required: Fortran interface for accessing new CDF-5 types

[dqwu]

PR #525 has introduced support for new CDF-5 external data types in SCORPIO. Presently, only the C interface has been updated to utilize these new data types. It is essential to extend this support to include the corresponding Fortran types (NF_*).

Additionally, the unit testing framework needs to be expanded to cover a broader range of data types.