[BUG]: The `quiver` trace ignores a discrete `marker.color` array and results in every arrow being black

Reproduce el problema mediante las llamadas a Plotly.newPlot en las herramientas de desarrollo del navegador, comenzando por la implementación del trace quiver. Compara el tratamiento del array discreto marker.color con el caso de una colorscale numérica y, después, verifica que cada flecha use su color correspondiente, mientras que los colores individuales y las colorscales sigan funcionando.

Description

The quiver trace ignores a discrete marker.color array. Every arrow ends up black instead of taking its per-point color. A numeric array with a colorscale works, and a single color string works.

Screenshots/Video

No colorscale (the bug)	With colorscale (for comparison)

Steps to reproduce

• Open plotly devtools
• Run the following snippet in the browser devtools console

   Plotly.newPlot(gd, [{
     type: 'quiver',
     x: [1, 2, 3], y: [1, 2, 3],
     u: [1, 1, 1], v: [0, 1, 0],
     marker: { color: ['rgb(23, 103, 194)', '#FF4136', '#2ECC40'], line: { width: 3 } }
   }]);
  

• Note that all three arrows are rgb(0, 0, 0) (by inspection of using your eyes)
• Run the following modified snippet:

   Plotly.newPlot(gd, [{
     type: 'quiver',
     x: [1, 2, 3], y: [1, 2, 3],
     u: [1, 1, 1], v: [0, 1, 0],
     marker: { color: [0, 5, 10], line: { width: 3 } },
     colorscale: 'Viridis'
   }]);
  

• Note that the arrows have the correct color

Notes

• marker.color is documented as arrayOk, so the black arrows seem to be a rendering bug (rather than an unsupported input)
• Per the schema, each arrow should be drawn as its own color from the array. If this behavior is intentional, we should update the description.
• This was found while working on #8025