dedicated histogram plotting function

[sebhahn]

the histogram plot (implemented here) using a custom colorbar should be a dedicated function that can be easily used externally by passing the correct arguments, since it can be quite useful for other (non-map) plots as well

[raphaelquast]

yep, I agree that it should be possible to allow using the "histogram on top of a colorbar" feature independent of EOmaps. (Could be quite useful as an "enhanced colorbar" for arbitrary matplotlib plots.)

However, there are still some open tasks in that feature that would be good to address as well:

• [x] #41 (they "borrow" space from the colorbar-axis, so the histogram-axis needs to reflect that)
• [ ] make sure all colormaps are properly handled (continuous, discrete, etc.) (no actual issues found so far but some tests would be nice to make sure)
• [ ] a "general" function probably needs better control on how to position the axes relative to the parent axes

If I find the time I'll look into this... meanwhile projects are always welcome! 🙂