Key bindings for navigating the displayed graph

[vogelsgesang]

I am personally a huge fan of using the keyboard for almost everything.
As such, it's pretty annoying not to have key-bindings available in query-graphs

I am not quite sure how a good set of key bindings would look like, but I think we will at least need bindings to:

• pan the displayed area of the tree (shift + left/right/up/down arrow keys?)
• zoom in/out (maybe overwrite the browser shortcuts Ctrl + and Ctrl -?)
• expand/collapse node
• mark a particular node as "hovered" -> display the tooltip information

nice to have:

• keyboard to follow "crosslink"

[rickcole]

Sounds like a good start.
For what it's worth, standalone-server/app.js defines keybinds for spacebar node expansion and key code debugging.