Add option to use SVV only in the spectral/hp expanions
This MR adds a new option SpectralVanishingViscositySpectralHP
that activates SVV in the spectral/hp expansion, but not in the homogeneous direction (the option SpectralVanishingViscosityHomo1D
was already available).
The behaviour when using the option SpectralVanishingViscosity
remains the same.