Users who don't own a code monitor have a bad experience when trying to view it

[benvenker]

Slack thread for context

If a non-owning user clicks on the "view" link in a code monitor Slack alert, they see this:

Next steps

• Decide on desired user experience (probably just need a "whoops, look like you can't edit this code monitor")
• Finish basic design
• Ticket out implementation work

/cc @benvenker @lguychard