Add reference results to PowerSystems_latest and PowerSystems_cpp

[sjoelund]

aa1cdfbe492ac7f80534282f97fd00bcbaf8be3d fixes so we extract the mat.xz-files from the repository and can merge this

[sjoelund]

https://libraries.openmodelica.org/branches/history/master/2021-12-16%2022:23:27..2021-12-17%2010:36:08.html