Would like the modebar to have a few more programmatic options, especially for extremely styled Dash apps:

1. Programmatic ability to set the modebar in a vertical orientation. Bokeh does a nice job with this:
   

2. Programmatic ability to set the background bar color, background bar opacity, and icon colors:
   

3. While we're at it, update the plotly logo in the modebar

Related:
#2171
https://github.com/plotly/streambed/issues/9699
(Perhaps we should create a plotly/plotly.js "modebar" label?)