[3p-doxygen] updated doxygen and copyright header for 3p test models

test/implicit/3p/infiltration3pproblem.hh

test/implicit/3p/infiltration3pspatialparams.hh

test/implicit/3p/test_box3p.cc

test/implicit/3p/test_cc3p.cc

test/implicit/3p3c/infiltrationproblem.hh

test/implicit/3p3c/infiltrationspatialparameters.hh

test/implicit/3p3c/test_box3p3c.cc

test/implicit/3p3c/test_cc3p3c.cc

test/implicit/3p3cni/columnxylolproblem.hh

test/implicit/3p3cni/columnxylolspatialparams.hh

test/implicit/3p3cni/kuevetteproblem.hh

test/implicit/3p3cni/kuevettespatialparams.hh

test/implicit/3p3cni/test_box3p3cni.cc

test/implicit/3p3cni/test_cc3p3cni.cc