Display error when comment can't be saved
Zendesk issue: https://gitlab.zendesk.com/agent/tickets/16197
Observed
If a user loses connectivity to GitLab for some reason, and is trying to submit a comment, they receive no feedback about what is happening. The 'Add comment' button greys out but there's no message indicating there is a connectivity problem.
Expected
After some time, display an error to the user. Since this seems to be JS can we do this?
cc/ @jschatz1