Coloc 2: Li 2 Histogram, enable selection fo whuch channel for y axis

added an argument in the constructor for as boolean telling if using ch1 or not
renamed getCh1BinWidth and getCh2BinWidth to getXBinWidth and getYBinWidth
to remove confusion.
Make 2 Li 2D Histograms , one for each channel on the Coloc_2 (controller)