cmake_parse_arguments: Add support for multiple list-value keyword arguments
#12650 (closed) made some progress but still doesn't support usages like:
my_func( COMMAND echo one two COMMAND echo three four )
Right now if I try this with the
multi_value_keywords option I just get a flat list like
echo;one;two;echo;three;four. Not sure how this would be best solved since lists of lists are not really supported in CMake...