Add server import support

[TwistedTwigleg]

As suggested by _eons on twitter

... An idea for a future feature: import from a server

I am not sure on the complexities this would entail, but it would be nice to have! My hunch is this could be supported using something like the HTTPRequest node.

(Also, just for kicks, it might be fun to add support to send DSCN files over Godot's high level networking API too 🙃 )