Add LayoutScene

[tectin0]

Hi team,

I'd like to discuss a few things. There are a few remaining TODOs that need your attention. One specific concern involves handling arguments below zero to AspectRatio - I'd appreciate your advice on how to approach this.

Additionally, do you think it would be a good idea to rename the struct LayoutScene to just Scene or Scene3D?

I also updated the customized_scatter3d_plot() example in the 3d_charts section. The example now includes most of the newly implemented fields and produces a very 'customized' plot.

I'm open to any feedback or suggestions you may have.

[mfreeborn]

Resolved everything :) When it comes to things like enforcing e.g. non-zero parameters to certain types like AspectRatio, we currently do the simplest thing of allowing the full range of values and let plotlyjs handle the problem. It will typically either clamp the provided value to the nearest valid value, substitute the invalid value with the default or ignore the argument altogether.