Supporting ViennaMaterials 'next' branch

ViennaMaterials commit: f4f8e60043da9ffcd1c95e614b67d9d57be798ec
supporting ViennaMesh/Grid next branches
working on 1d capacitor device example

using ViennaMesh's generation capabilities
1d capacitor compiles and executes
1d capacitor for different 'eps' values

using this example for the viennamaterials journal paper.
investigating coupling between model-based simulation parameter and simulation.

hijacking the 'eps' parameter of the Laplace equation used in semiconductor device simulation
in combination with new 'dummy' material providing a model-based eps parameter,
depending on the temperature
Merge branch 'vmesh_api' into next
updated 1d capacitor example
Merge branch '1dcap' into next
add viennamesh to the viennamini lib dependency
extended config class to support setting filenames
Merge branch 'device_suite' into next
added 'write_vtk' method to device + some debugging

write_vtk(filename) allows to write the raw mesh to PVD/VTU files

debugging related to examining SingleGate simulation problems.
-> turns out, that the input PVD/VTU files are faulty
Merge branch 'next' into device_suite