Allow style editing of graph legend labels

Thanks so much for your interest in Dash!

The feature has already been tangentially discussed here: https://community.plotly.com/t/scatter-plot-how-to-wrap-legends-text-when-legend-text-is-too-long/4767/7

Is your feature request related to a problem? Please describe.
I have traces that have very long names. It's problematic because the legend text does not word wrap and so it squishes the graph.
Here's an example: https://postimg.cc/VSq0bQXW

Describe the solution you'd like
Please allow for more stylistic control over legend text, particularly allowing for textoverflow control, like word wrap, hidden+ellipsis, hover tooltip etc.

Describe alternatives you've considered
I had to resorted to displaying a hashmap to translate the long text into a shorter signature.

Additional context
I've had it where the text is really long that the actual graph is completely unreadable.

Inizia riproducendo il problema con traces che hanno nomi molto lunghi e consulta la discussione della community collegata sul comportamento richiesto della legenda. Chiarisci quali opzioni di overflow devono essere supportate, quindi verifica che il grafico rimanga leggibile con etichette lunghe e che il comportamento selezionato sia visibile agli utenti.