Generic to Schema Refactor

[Jan-Willem]

The file src/xradio/_utils/schema.py has utility functions that convert 'generic' xds's to the new schema. The function schema.py::convert_generic_xds_to_xradio_schema is now used in src/xradio/vis/_vis_utils/_ms/create_antenna_xds.py.

The following functions should be updated to make use of convert_generic_xds_to_xradio_schema

• [x] src/xradio/vis/_vis_utils/_ms/create_field_and_source_xds.py
• [x] src/xradio/vis/_vis_utils/_ms/msv4_sub_xdss.py
• [ ] src/xradio/vis/_vis_utils/_ms/conversion.py

[FedeMPouzols]

This branch has now the refactored versions of create_weather_xds()/create_pointing_xds()/extract_field_info_and_check_ephemeris()/extract_field_info_and_check_ephemeris()/extract_source_info()/extract_ephemeris_info(). In conversion.py I didn't see much potential for convert_generic_xds_to_xradio_schema() as the main table is treated in a very specific way whereby most columns are handled individually.

This also reorganizes a few more related places in the code:

• in extract_source_info and extract_field_info_and_check_ephemeris, I've also taken out some code that can live more happily and organized in their own functions.
• in pointing_xds there is also similar additional refactoring for the "dimension fixes" needed on the generic_xds before conversion.