A function to reorganize the PDE model output into a more intuitive form

[aarmey]

The compartmental model is organized as 27 species repeated for each position in a radially-symmetric geometry. Thus, with 100 points, the answer is 2700x(# tps). It'd be helpful to organize this to be 100x27x(# tps), so that one can easily index/slice parts of interest.

[aarmey]

This would make plotting and using the output of the compartmental model much easier. @sumedha-k, perhaps you can work with @ajtsao1 on this and the plotting she has been setting up? They're both co-dependent issues but necessary to be able to look at the model with PS.

[aarmey]

I believe this is done on #267. It'd be nice to have a test for this—we can discuss possibilities.