Exit sub network with escape

[timon-schelling]

Pressing escape inside a sub network should move up one level instead of closing the node graph.

[Sambhram1]

can you please assign me this

[Keavon]

You're welcome to begin implementing it and open a PR. Assignments will occur after a PR is merged.

[Sambhram1]

#3285 tried to solve this issue

[j-jasz]

That is exactly the same issue as: #3214
After looking into proposed PR above I'm also in a favor of doing this with Esc instead of Backspace that I proposed in my ticket.