[freeflow][spatialparams] Add base and default freeflow spatialparams classes

dumux/freeflow/navierstokes/mass/1p/model.hh

dumux/freeflow/properties.hh

dumux/freeflow/spatialparams.hh

examples/shallowwaterfriction/spatialparams.hh

test/freeflow/navierstokes/channel/3d/spatialparams.hh

test/freeflow/shallowwater/bowl/spatialparams.hh

test/freeflow/shallowwater/dambreak/spatialparams.hh

test/freeflow/shallowwater/poiseuilleflow/spatialparams.hh

test/freeflow/shallowwater/roughchannel/spatialparams.hh