Keep links in SVG exports

[anthonyvdotbe]

Is your feature request related to a problem? Please describe.

When I export to SVG, I'd like the nodes to keep their links.

Additional context

Below is a mind map I've exported to SVG. I manually edited the SVG by simply adding <a xlink:href= "https://github.com/freeplane/freeplane"> before the opening text tag and </a> after the closing text tag. So it seems this should be relatively easy for Freeplane to do automatically.