Cleanup/interfacial areas

• create test for cctpfa nonequilibrium
• cleanup thermal non-equilibrium localresidual: qBoil is a special case which should not be calculated for all models with 1 liquid energy equation
• for 1 energyequation for the fluid: remove interfacial area calculation from localresidual but instead transfer that to spatialparams/volumevariables

Fixes #555 (closed), closes #566 (closed)