Merge branch '11-sine-and-cosine-transforms-to-solve-homogeneous-neumann-and-dirichlet-problems' into 'master'

Resolve "Sine and cosine transforms to solve homogeneous Neumann and Dirichlet problems"

Closes #11

See merge request !3

Merge branch '11-sine-and-cosine-transforms-to-solve-homogeneous-neumann-and-dirichlet-problems' of gricad-gitlab.univ-grenoble-alpes.fr:particle_methods/hysop into 11-sine-and-cosine-transforms-to-solve-homogeneous-neumann-and-dirichlet-problems

Merge branch '11-sine-and-cosine-transforms-to-solve-homogeneous-neumann-and-dirichlet-problems' of gitlab.com:keckj/hysop into 11-sine-and-cosine-transforms-to-solve-homogeneous-neumann-and-dirichlet-problems