Add support for legend and colormap

[prudhomm]

The legend cannot be moved at the moved neither configured

• change the text of the legend

• move the legend and allow vertical/horizontal layout

• change the colormap (eg rainbow,...)

• [x] reset data range

• [x] rescale data rage

• [x] log scale

• [x] change color map preset (take first 5: and among them rainbow)

/cc @vincentchabannes

[felixveysseyre]

Implemented with commits: e19a2aa11967c7b719d8222221cd1ec7079dc5a6, f535c776c3a0652be6d8c96ef19254398b5827ed, 1047453c7edbef735dc370fc58173f1dd01d79ca, 13f6187f6b2eeb4769c6c655b890c9d3e2533945