Meteogram - Improvements

[guidocioni]

Wind Arrows
Find a way to pivot the arrows around the center of the coordinate, and not the tip. Using other markers (like triangle) unfortunately doesn't really work because they're symmetric so that they don't really tell a direction. One way would be to re-use some part of the quiver function from the figure factory (https://github.com/plotly/plotly.py/blob/master/packages/python/plotly/plotly/figure_factory/_quiver.py) which basically does nothing more than constructing the arrows manually with lines.

Winds
If winds are over a certain threshold put the gusts with an interval as done in meteoblue

Snow
Only when there is snow predicted, put just a number close to the precipitation probability which indicates the snow probability.

Precipitation hours
Would be good to find a place for this...but I'm not sure where to put it.

Sunshine hours
Right now if there are no sunshine hours predicted nothing gets plotted. This is confused, it would be better to put 0 hours on the plot