This commit does quite a bit:
- Catches unhandled exceptions raised in the route handler and
produces a 500 Internal Server Error Arch-themed response.
- Each unhandled exception causes a notification to be sent to new
`notifications.postmaster` email with a "Traceback ID."
- Traceback ID is logged to the server along with the traceback which
caused the 500: `docker-compose logs fastapi | grep '<traceback_id>'`
- If `options.traceback` is set to `1`, traceback is displayed in
the new 500.html template.
Signed-off-by: Kevin Morris <kevr@0cost.org>
