Add 2D triangulation plot

It would be very useful for me adding a new chart type to deal with 2D triangulation (or mesh).

At the current implementation, I found different workarounds but with some limitations:

• the heatmap graph is only for data in grid format
• the mesh3d graph shows three dimensions and it manages also the lights, resulting for my purpose too complex (and expensive)
• the basic scatter plot allows me to draw a single triangle, but if I try for many triangles (>10k) the function is extremely expensive.

I apologize in advance if this feature is already implemented and I missed it.

Inizia esaminando le implementazioni esistenti dei grafici heatmap, mesh3d e scatter per comprenderne i limiti relativi ai dati e al rendering. Definisci gli input previsti per la triangolazione 2D o la mesh, il comportamento del rendering e l’obiettivo di prestazioni per un numero elevato di triangoli prima di proporre il nuovo tipo di grafico.