Consider export of fault surface data in a simplistic manner

[ErichSuter]

The newer RMS-versions allow export of fault surfaces as triangulations (GoCad TSurf format).
This data is useful to several applications.
But export of triangulated fault surfaces to Sumo via xtgeo/fmu-dataio is not possible today.
Clearly, native support of such surfaces and potentially related attributes is a larger task which is not discussed here.

The immediate question at hand is if it is possible to export such data to Sumo in a form where consumers, with additional efforts on their side, may still be able to apply it in a meaningful manner.

Also see discussion on Slack: https://equinor.slack.com/archives/C06E3UTGTEV/p1715694922594139