Harmonize input file names and CMakeLists.txt

Closes #4

See merge request !62

Cleanup/free spatialparams from typetag

See merge request !63

Make solution files and exercise files more equal

[exercises][dunemodule] Update statements corresponding to opts files.

Closes #6

See merge request !60

Cleanup/remove type tag ending

See merge request !59

removed TypeTags endings and changed names of struct, if necessary

removed TypeTag ending and and added suffix NC for Stokes and OnePNC for Darcy

removed TypeTag ending

[exercise-basic]

See merge request !58

removed TypeTag ending

removed TypeTag ending

removed TypeTag ending

removed TypeTag ending

removed TypeTag ending

removed TypeTag Endungen

update dumux-course to dumux 3.0

See merge request !54

[script] checkout the correct release

See merge request !56

update readme

changed captions Task 2, Task 3 and Task 4 to appear bold in the readme

Fix free flow porous medium coupling

See merge request !55

-updated to dumux 3.0
-added a build-directory for the solution

changed to
box.hh
cctpfa.hh
ccmpfa.hh

removed Task 3; Properties::print<TypeTag>(); doesn't exist anymore