[plotly] jump to custom data index if available

[PythonFZ]

If you provide customdata, e.g. via

l1 = pd.DataFrame({"x": [1, 2, 3], "y": [0, 1, 2], "idx": [0, 1, 2], "line_id": "line_1"})
l2 = pd.DataFrame({"x": [1, 2, 3], "y": [0.5, 1.5, 2.5], "idx": [3, 4, 5], "line_id": "line_2"})

# Combine the DataFrames
df = pd.concat([l1, l2])

# Plotting the lines
fig = px.line(df, x="x", y="y", color="line_id", hover_data=["idx"])
vis.figure = fig.to_json()

plotly will jump to the first item in customdata instead of the pointIndex.