Read 2D map for different providers and return data in a Map2D class element.
Each provider can cover multiple SWD tables:
- WSO: ascii from OBS_MAPS_WSO
- NSO/GONG: fits from OBS_MAPS_NSO
- ADAPT/GONG: fits from OBS_MAPS_ADAPT40 and OBS_MAPS_ADAPT41
- SDO/AIA: fits from OBS_MAPS_SDO_AIA_171 and SDO_AIA_193
- SDO/HMI: fits from OBS_MAPS_SDO_HMI
- SOHO/EIT: fits from OBS_MAPS_SOHO_EIT_171 and OBS_MAPS_SOHO_EIT_195
- EUV2CARMAP/SDOSTA: fits from OBS_MAPS_EUV2CARMAP_SDOSTA_*
- WL2CARMAP/SOHOLASCO: fits from OBS_MAPS_WL2CARMAP_SOHOLASCO_*
- ASCII_MAP2D: ascii file produced by standard ascii map2D IO routines.
- EUV2CARMAP/SDO360: fits from OBS_MAPS_EUV2CARMAP_SDO360_*