QA: Integrate available open data about substations in Osmose in merge analysers

[flacombe]

Produce warnings about missing substations available in open data.

Example in France: https://github.com/osm-fr/osmose-backend/blob/dev/analysers/analyser_merge_power_substation_FR.py

[nlehuby]

this one is a good candidate, assuming the license is ok (?): https://energydata.info/dataset/eswatini-substations