WIP: Feature/new ic condition2

What this MR does / why does DuMux need it: This MR implements new coupling conditions for stokes-darcy interfaces, as proposed/described by Elissa Eggenweiler. The new interface conditions are meant to be more general and appropriate in comparison to the Beavers-Joseph condition and the current normal momentum coupling.

TODO:

• Combine new/standardPorousMediumVelocity, beaversJoseph/nTangentialVelocity and old/newMomentumCouplingCondition
• Allow unsymmetrizedStressTensorForBJ and unsymmetrizedStressTensorForIC!
• Set up two tests: Beaver-Josephs and newIC, see: dumux/test/multidomain/boundary/stokesdarcy/1p_1p, @Elissa
• Check deprecation and documentation, link to paper from Elissa?
• Add warning for newIC with symmetrized tensor
• Folder and file names should not contain capital letters.
• Follow styleguide: Correct indent, curly braces
• Small TODOs in project

Special notes for your reviewer: I appreciate all help regarding the technicalities of the merge request.