Method to center the camera / viewport on the selected node from plugin and tool mode

[pixel-boy]

I was trying to center the scene editor view on the selected node (like the shortcut "F") via a plugin and I haven't really found a way to do it easily, and even with the workarounds it seems quite complicated.

I was thinking that having this functionality via the EditorInterface could be interesting.

I opened a reddit post about that:
https://www.reddit.com/r/godot/comments/1g1d4uv/center_scene_editor_camera_viewport_to_node_from/