Adds the SHARE regionalisation to the regionalisation files and re-name files for better consistency
To facilitate shakyground2 becoming a tool for eGSIM, the SHARE regionalisation is implemented according to the json/geojson structure adopted for other regionalisations. Note here that the SHARE regionalisation is not used in the global default regionalisation, where it is superseded by the ESHM20 regionalisation.
In the process, some file re-naming is done to apply a more consistent naming scheme. Now the files for region xyz should be xyz.geojson, which includes the geospatial information, and xyz.json for the GMM mapping.