Script based domain conversion

[jcrivenaes]

Instead of using RMS jobs with interval velocities cubes, rather use a script using average velocities (or slowness) from time-depth pairs to do domain convert in the sim2seis and geo2seis work flows.

This is related to development om DomainConversion in fmu.tools.

[rnyb]

This will be included as part of the fmu-sim2seis work