Improvement on results (3): Raman and IR spectra parameters and polar plots

[mikibonacci]

Raman and IR spectra improvement:

• show both IR and Raman: now we should have them at the same time
• add reset button for parameters
• add filter for too low intensity modes. #45
• all properties should be downloadable (also phononic one... for now this is not true)

In principle, it is possible to define HH/VV and HV geometries for the scattering spectra (backward or 90 degree deviation geometries). In principle, this can be defined as input when spectra are computed; #43

• Intensity average workchain.
• understand how you can define these in/out directions in the functions. In principle this can be defined via q=k_in-k_out

the light polarization is another thing, and is the one already defined in our widgets.

Polar plots:

In principle, one can define the spectra intensity for a range of polarization, being then angle dependent, and plot in a so-called polar plot. We should define input and output polarization in function of this angle, and plot for [0,2pi]/N, where N is the number of point on the cirumference.