Default graph view in huge workflows

[mcastril]

The Graph default view tries to cover the full workflow at the start and this is not very useful in huge workflows like the Climate DT ones.

One can see a very thin line that disappears (hangs) once you try to zoom or pan the image.

https://climatedt-wf.csc.fi/experiment/a0yd/graph

https://climatedt-wf.csc.fi/experiment/a27y/graph

I understand it's difficult to use the Graph in these situations, but I thought that in large workflows we could make it focus on the Active tasks by default, so it should be something useful

If there are many Active tasks, we could just select one and do a medium zoom

Even if we cannot pan or zoom, this will already show some practical information

[LuiggiTenorioK]

Cytoscape.js (the new lib we use to render the graph in the GUI) is working in a WebGL renderer and already has a preview of this new feature: https://blog.js.cytoscape.org/2025/01/13/webgl-preview/

Adopting it in the future will be a great improvement to handle the massive graphs that we have now. Still, we'll need to adopt better strategies to handle the huge amount of data on memory.