Add setting to hide Plotly mode bar

I find that the “mode bar” on Plotly charts can be confusing to people and doesn’t add any value in our use of Redash. Hiding it is as simple as adding displayModeBar: false to the Plotly configuration.

I’m happy to submit a PR and make it a setting on the organization (“Hide mode bar”), but before doing so wanted to check if there was support for this idea?

I’d love this, personally. I use plotly all over the place and basically never show the Mode Bar.

Great. PR submitted