Better feature summary and overview

[mfherbst]

Integrate molsturm and the dependent packages with the cmake mode FeatureSummary in order to make it easier to manage and show the list of features and which are enabled. Probably it is a good idea to integrate this somehow into krims/cmake/modules/ProjectFeatures.cmake.

This integration of FeatureSummary is especially important for

• [ ] lazyten (backend libraries and solvers)
• [ ] gint (integral libraries)
• [ ] molsturm (e.g. python packages and 3rd party libraries)