The new loadbalancer approach will create a graph representing the grid
where all cells that a well perforates are represented by one
vertex. The weight of that cell will be the number of cells it
represents. Also the weights of the faces will be added up due to the
merging of cells. A cell that is not perforated by any well is still
represented by one vertex with weight one.
In the old default appoach the number of vertices in the grid was
equal to the number of cells. Vertex weights were not used. For each
well we added an edge between all its perforated cells for which we
did set a very edge weight to force the cells to the same process
during partitioning.
For realistic cases we have seen improvements across the board due to
this. E.g. this resolved convergence issues on hard cases. Because of
that this becomes the default with this.
This PR switches to calling the SummaryState constructor which is
aware of the value of undefined UDQs (OPM/opm-common#4052) directly.
While here, also sort headers, split some long lines, and prefer
initialisation lists to constructor body assignments.
