[Feature Request] Stack trace on deadlock exception improvements

[cretz]

Describe the solution you'd like

#626 added a stack traces from the deadlocking thread, but there are three improvements we need to make to make sure this is working properly:

1. Make this also work for users that have opted out of sandboxing (if, as suspected reading the PR, it doesn't actually work already)
2. Add a test to confirm the deadlock stack trace represents (couldn't see such a test in the PR)
3. We append (no frames available) or (failed getting frames: {err}) when we couldn't capture the threads trace, but we should also add something like (no thread ID available) if the earlier condition occurs where for some reason we don't have a thread ID at all.