[NAD] Add network name in the metadata

[flo-dup]

Describe the current behavior

The generated diagram (SVG + JSON) does not contain any information about the network displayed (name, date)

Describe the expected behavior

The generated diagram (SVG + JSON) contains information about the network name, at least the name

Describe the motivation

When exporting the diagram in png or svg with powsybl-network-viewer, the resulting file cannot be named better than nad.svg / nad.png.

Extra Information

No response

[hqqw2h-lgtm]

Hi, I'd like to work on this as well. I'll add the network name to the NAD metadata.