Since we are now using "devtools/shared/dom-node-constants" in Reps, the JSONView
was failing. Add "devtools/shared" to the requirejs configuration to allow the JSONView
to require the script, and wrap the dom-node-constants export in `define` since the view
expect the modules to be AMD.
MozReview-Commit-ID: CXQZ0YzrWGV