Some of our computations are heavily serial and need a complete
representation of the data attached to all perforation no matter
whether a perforation lives on the local partition or not. This commit
adds a factory that allows to easily create such a representaion and
helps writing data back to the local representation.
As this is as sequential (ordering matters!) as it can get we need to
communicate all perforations, do the partial sum with them and save
result back to the local perforations.
This adds an utility that creates a vector of all above values for
the local perforations. For distributed wells this is needed as the
perforation above might live on another processor. We use the parallel
index sets together with the global index of the cells that are
perforated.
BlackoilWellModel now stores an instance of this class for each
well. Inside that class there is a custom communicator that only
contains ranks that will have local cells perforated by the well.
This will be used in the application of the distributed well operator.
This is another small step in the direction of distributed wells,
but it should be safe to merge this (note creation of the custom
communicators is a collective operation in MPI but done only once).
