Add ability to open selected file

[kevinsawicki]

Double clicking a file from the graph tab should open it.

[zeke]

In atom? With atom://?

[parro-it]

I think it should be better to open it in devtools.
Not everyone is using atom

[wineerteam]

I’d like to work on this issue for my GSoC contribution.
If it’s free, can I start working on it?