Create a solver ctest

[weinbe2]

We should add a ctest which covers at least the most commonly used solvers, sweeping over (as appropriate for the compile):

• Wilson- and staggered-type fermions.
• All mixed precision combinations
• CG, Multishift CG, BiCGStab, GCR, CA-GCR (plus others? I don't see a need to cover everything)

I believe this should cover the non-MG workflows for most major applications.

While not strictly required, this should include addressing #949 for stronger reproducibility.