[test][cleanup] general cleanup, remove whitespace, indentation

dumux/discretization/box/fourierslawnonequilibrium.hh

...retization/cellcentered/tpfa/fourierslawnonequilibrium.hh

...trixinteractions/1pia/fluidsolidinterfacialareashiwang.hh

dumux/material/fluidmatrixinteractions/mp/mpadapter.hh

dumux/material/spatialparams/fvnonequilibrium.hh

dumux/porousmediumflow/1pnc/model.hh

dumux/porousmediumflow/mpnc/volumevariables.hh

.../porousmediumflow/nonequilibrium/thermal/localresidual.hh

test/porousmediumflow/mpnc/implicit/kinetic/problem.hh

...implicit/thermalnonequilibrium/combustionlocalresidual.hh

...mediumflow/mpnc/implicit/thermalnonequilibrium/problem.hh