[BugFix] Set Chart Style Before Output

[deeleeramone]

1. Why?:

   • The basic theme for charts was relying on the plotly.html file to set the theme as light/dark mode. For users relying on inline display, the result was a figure with an unset background.

Before:

This can be observed from, res.chart.fig

2. What? (1-3 sentences or a bullet point list):

   • Insert a method that reads the user preference for chart_style and then sets the paper_bgcolor and font_color accordingly.
   • Add a simple class method for toggling this choice on a generated figure.

3. Impact (1-2 sentences or a bullet point list):

   • This ensures that the inline renders display correctly.

4. Testing Done:

data = obb.equity.price.historical("AAPL", chart=True)
data.chart.fig

After:

This will update the figure to be the reverse of the chart_style preference. It does not render the update, show() must be used after.

data.charting.toggle_chart_style()