Rename FVSpatialParams to SequentialFVSpatialParams

dumux/material/spatialparams/fv.hh

dumux/material/spatialparams/fv1p.hh

dumux/porousmediumflow/1p/sequential/properties.hh

dumux/porousmediumflow/2p/sequential/properties.hh

dumux/porousmediumflow/2p2c/sequential/properties.hh

test/porousmediumflow/1p/sequential/test_1pspatialparams.hh

...usmediumflow/1p/sequential/test_diffusionspatialparams.hh

...mediumflow/1p/sequential/test_diffusionspatialparams3d.hh

.../porousmediumflow/2p/sequential/test_3d2pspatialparams.hh

...diumflow/2p/sequential/test_impesadaptivespatialparams.hh

...porousmediumflow/2p/sequential/test_impesspatialparams.hh

...orousmediumflow/2p/sequential/test_mpfa2pspatialparams.hh

...usmediumflow/2p/sequential/test_transportspatialparams.hh

...smediumflow/2p2c/sequential/test_dec2p2c_spatialparams.hh