- add `x` and `y` attributes to the Spectrum
- remove forceDim1 and forceDim2 for force_dims which take the two dimensions as input and recompute the Spectrums indices.
warning: this could effect the display of Spectra in the future. So this should be defined before tretatment and keep for the life of the object.
note: the roi process is creating a new Spectra so will not be an issue