Phases in simulation model

[anders-kiaer]

Original author: @olelod

Currently the phases of the model are extracted from the relative permeability given.

    if self._swof and self._sgof:
        str_runspec_section = "OIL\nWATER\nGAS\n"
    elif self._swof:
        str_runspec_section = "OIL\nWATER\n"
    elif self._sgof:
        str_runspec_section = "OIL\nGAS\n"

    return {
        "RUNSPEC": str_runspec_section,
        "REGIONS": write_grdecl_file(merged_df_satnum, "SATNUM", int_type=True),
        "PROPS": str_props_section,
    }

Should we reverse this and make the user provide which phases are present in the config yaml? This would make it easier to check if the input needed is provided (relperm, contacts etc.).