Test output now shows the module name left-aligned so you can easily
browse to see what modules have what tests and know what module a
failing test is coming from.
SFML convention is to only use "" includes when the header is in
the same directory as the file including it. Because these test
util headers are in a separate directory, it makes more sense to
include them via <>.
Both ApproxVec and ApproxDeg accept a double then convert that to
a float just to then convert it back to a double. We can save an
extra lossy conversion by just accepting a float instead of a double
in the first place.