Update nrar import to be consistent with sxs updated package

[divyajyoti09]

sxs package has transported nrar.py to format_handlers directory. Hence updating the import.

[adivijaykumar]

Thanks @divyajyoti09! This change also means that there would be a minimum supported version of the sxs package. Could you edit the requirements.txt file to ensure sxs >= v2023.0.0?

[prayush]

Thanks @divyajyoti09! This change also means that there would be a minimum supported version of the sxs package. Could you edit the requirements.txt file to ensure sxs >= v2023.0.0?

merged with #43