Fix all typos found by 'codespell'

dune/gfe/averageinterface.hh

dune/gfe/embeddedglobalgfefunction.hh

dune/gfe/geodesicfeassemblerwrapper.hh

dune/gfe/globalgeodesicfefunction.hh

dune/gfe/linearalgebra.hh

dune/gfe/localquickanddirtyfefunction.hh

dune/gfe/mixedriemanniantrsolver.cc

dune/gfe/polardecomposition.hh

dune/gfe/realtuple.hh

dune/gfe/riemannianpnsolver.cc

dune/gfe/riemanniantrsolver.cc

dune/gfe/rigidbodymotion.hh

dune/gfe/rotation.hh

dune/gfe/skewmatrix.hh

dune/gfe/surfacecosseratenergy.hh

dune/gfe/surfacecosseratstressassembler.hh

dune/gfe/svd.hh

dune/gfe/targetspacertrsolver.cc

dune/gfe/unitvector.hh

src/rodobstacle.cc