Add a way to open files from the error box

[gaearon]

We should add something like this to our devserver, and then make lines in the crash overlay call the devserver (opening the files).

[gaearon]

This is basically what RN is using: https://github.com/facebook/react-native/blob/118e981174ae513426e2f5ddd7ee3c5860519ff7/local-cli/server/middleware/openStackFrameInEditorMiddleware.js.

[Timer]

#2141

[gaearon]

We should probably add back the code that prints instructions when the editor hasn't matched. RN had code for this but I cut it out because I didn't want to test it. I'd like to keep it open until we have time to add that back in.

[Timer]

Sorry, wasn't aware! 😅