More control about DPStokes parameters

[RaulPPelaez]

We could use this script to allow for more control of the DPStokes parameters:
https://github.com/stochasticHydroTools/DoublyPeriodicStokes/blob/main/source/cpu/python/GridAndKernelConfig.py

[rykerfish]

From a recent discussion, this issue is going to get refocused into adding the ability to select different kernel widths ($w$ or $m$ depending on the reference) and automatically select parameters for those kernels. The scope will be limited to kernels where optimal parameters are given in the original DPStokes paper. If we ever want to add polydispersity similar to the script linked above, we can try that in another issue.