Adding hurs (realtive humidity) derivation script

[malininae]

Hi folks,

Following the April 2024 monthly meeting, I'm adding the relative humidity derivation (hurs). Before being able to open a real PR, I would need to add filtering in case the hurs_cb.data >100%. Also need to write test. Will do it before the workshop.

This PR is related to #2254 .

[bouweandela]

would need to add filtering in case the hurs_cb.data >100%

This could probably be done with code like this:

import dask.array as da
hurs_cb.data = da.ma.where(hurs_cb.core_data() > 100., hurs_cb.core_data(), 100.)

[bouweandela]

If you would like a quicker response in the future, it usually helps if you tag people so they get a notification, e.g. @bouweandela