Code review comment for lp://qastaging/~osomon/webbrowser-app/oxide-context-menu

Works mostly as expected on desktop. Have not tested on device yet or ran tests myself.

I included various comments inline based on review of the code.

I am not sure if revision 1133 belongs in this MR, even though I understand why it was easy to include it. Up to you if you want to consider splitting it off, but it would certainly seem cleaner from a repository cleanliness point of view.