Do not automatically quote all CMake definition values passed as arguments

Fixes #286 (closed)

This solves the issue on Jammy that C compiler flags set in a module definition (in this case the azure kinect sensor SDK) are interpreted as one single argument.

So setting

CMAKE_C_COMPILE_FLAGS to -x one thing -y another thing -z something will be interpreted and passed to the compiler as one flag instead of 3, namely -x -y and -z with their values.

Some modules may already define a variable and want it to be interpreted as a single string. This fix might break this behavior now, but then the corresponding module definitions have to be fixed by quoting the value in the string.