Tests: Refactor tests with better names, etc.

The basic tests now run on Windows correctly without needing to manually
copy any files -- the executables are output in the same location as the
necessary DLLs. However, tests that require *.pyd files (all code in the
Mod subdirectory, basically) still do not work on Windows as the test
executables cannot find those files. This is a work in progress.

tests/src/Misc/fmt.cpp

@@ -1,5 +1,5 @@
-#include "fmt/format.h"
-#include "fmt/printf.h"
+#include <fmt/format.h>
+#include <fmt/printf.h>
 #include <gtest/gtest.h>
 #include <stdexcept>