Adjust WVS to return sum(s) for each dimensionality

[markcmiller86]

Is your feature request related to a problem?

We have the ability to compute a weighted variable sum. The weighting is determined by a property of the element. For a set of 3D mesh elements, the weighting is the volume of the elements. For a set of 2D mesh elements, it is the area, etc.

For a mesh consisting of a mixture of different element dimensionalities, I think we currently do something quite odd that involves combining (e.g. summing) results from different dimensionalities.

We should instead return multiple sums, one for each element demensionality (0,1,2,3). In addition, why maintain two queries each doing the same thing one with weighting and one without. Why not just a single variable sum query in which the user checks a box as to whether (or maybe whatkind of) weigting should be applied. Or, again, just have the query return both and let the user choose which value(s) they want to pay attention to. If you happen to want/need both, you don't have to make multiple passes over the data to get it. So, a query result might look like...

variable sum of 0 dimensional entities = 2.7
variable sum of 1 dimensional entities = 42
variable sum of 2 dimensional entities = 0
variable sum of 3 dimensional entities = 1234

weighted variable sum of 0 dimensional entities = 1.9
weighted variable sum of 1 dimensional entities = 21
weighted variable sum of 2 dimensional entities = 0
weighted variable sum of 3 dimensional entities = 555

[rusu24edward]

Related discussion in #4063