smoothly migrate ssystem_minor.ini (and other datafiles)

[axd1967]

Similar to #4026 :

Found in logfile:

Minor body  2010 TK7 has incomplete data (missing iau_designation or minor_planet_number) 
...
Old-fashioned entry "comet_orbit" found. Please delete line from  "/home/alex/projects/stellarium/configs/master/data/ssystem_minor.ini" section "p2020x1(atlas)"
,,,

proposal

Use a migration pattern to smoothly migrate older formats; the average user will not always check the logfile and/or be even able to do this.

workaround

reset ssystem_minor.ini (and lose a lot of customization).

[gzotti]

These messages are informative only. Objects are still loaded. "comet_orbit" has been replaced by kepler_orbit which is the default. Missing name parts are just not available for search/name formation.

If you use older versions of the program in parallel, you may need the old entries. If not, you can delete them.

The missing name parts cannot be reverse-parsed from possible old name entries which may come in various styles, this is the reason to split those name bits in the first place.

[github-actions]

This is not a bug! This is a feature...