Implement hovertemplate for candlestick and ohlc traces

[emilykl]

Closes#3437

This PR adds a hovertemplate attribute for ohlc and candlestick, allowing users to define a custom hover template for those traces.

hovertemplate: 'opened at %{open}<br>closed at %{close}<extra></extra>',

Notes

• The first commit of this PR runs the biome formatter which introduces some noise into the diff. Use this link to see only the meaningful changes.

• This PR also adds the hovertemplatefallback attribute for the two traces in question

• hovertemplate is ignored when hoverlabel.split is set to true. (Open to suggestions here but I couldn't see an obvious way to make split: true work with the hovertemplate API.)

• Two Jasmine tests added

This completes the list in #3437.

Thanks to @chriddyp for putting this on my radar!

To test

• Create a plot like this one:

Plotly.newPlot("plot",[{x: [1,2,3,4,5],low: [21,13,18,16,22],high: [34,23,25,26,24],open: [24,16,22,23,22],close: [22,18,21,21,23],type: 'candlestick',// or 'ohlc'hovertemplate: 'opened at %{open}<br>closed at %{close}<extra></extra>',// hoverlabel: {split: true}, // if the above line is uncommented, `hovertemplate` should be ignored// and separate hover tooltips should be shown for open, high, low, and close}],);

• Hover over the data and confirm that the hovertemplate is respected
• Confirm that if hoverlabel.split is set to true, the hovertemplate is ignored and the previous behavior is unchanged

[camdecoster]

As we discussed, there's an issue with implementing the split: true logic that makes the split hover info not show up. Could you look into that?

[emilykl]

@camdecoster The bug you found with split: true should be fixed now. Ready for another look. I also added a Jasmine test which tests split: true and hovertemplate together.

[camdecoster]

Looks good. Could you please add a draftlog before merging?