Replace the integer eclipse_case_id parameter on
RimcWellEventTimeline_generateSchedule with a
caf::PdmPtrField<RimEclipseCase*>. The execute() method no longer needs
to walk the project tree and look up the case by ID — the gRPC layer
resolves the object pointer for us.
generate_schedule_text passes the Eclipse case object through to the
underlying generate_schedule call, matching how add_perf_event /
add_well_keyword_event already take a WellPath object rather than an
ID.