Adds case.filtered_cells(filter, time_step, grid_index) which applies any
RimCellFilter to an Eclipse case and returns a per-cell 0/1 mask. The mask
length and ordering match case.grid_property(..., grid_index), so callers
can combine the two vectors element-wise.
Implemented as a scriptable Rimc method (PdmVoidObjectMethod) on
RimEclipseCase that writes the mask via the existing key-value store, with
a thin Python wrapper mirroring the visible_cells() pattern. No proto or
gRPC service changes.
Kristian Bendiksen
ddcfef736b