`python`: Inconsistency between RIPS and GUI for `add_diameter_roughness_interval` and `add_custom_segment_interval` API

[alifbe]

The API add_diameter_roughness_interval is located under WellPathCompletionSettings class. But in GUI, it is displayed under Multi Segment Well Options (which I think is the proper place for it)

Suggestion to move this API to MswSettings instead.

https://api.resinsight.org/en/main/api/rips.WellPathCompletionSettings.html#rips.WellPathCompletionSettings.add_diameter_roughness_interval