`SCDNA` dataset to be added

[kasra-keshavarz]

Problem

The SCDNA dataset to be added to the list of datasets.

Extra information

The relevant information could be found in the following: https://uofs-comphyd.github.io/group_datasets/SCDNA

[kasra-keshavarz]

The structure of the dataset proved to be not super user-friendly. This needs to be dealt with separately.

[ShervanGharari]

Indeed, SCDNA is not a homogenous set of stations, a subset of stations can be extracted for different organizations and variables. This might be helpful in dealing with SCDNA:
https://github.com/ShervanGharari/EASYMORE/blob/main/examples/04_Thiessen_Polygons_SCDNA.ipynb
It is a light dataset, easier to take care of it outside of the datatool.