Review temperature mode discovery in python tests

Recently, this solution to automatically let the python tests determine which temperature mode to use was implemented: ccee95e7

Euler does not seem to like this solution (the metadata.o file is not compatible there). @webmanue came up with a much simpler solution: Name the binaries after the temperature mode, e.g. Relaxation3D_0K.exe, Relaxation3D_FINITE_K.exe (maybe you have better suffixes). This would also have the advantage, that we could have both versions together at the same time.