Check stack traces and use backward-cpp if it isn't working

[varungandhi-src]

A customer reported that they didn't get a stack trace on a segfault, I thought we already had code which handled this. We should manually test if this works and set up https://github.com/bombela/backward-cpp if it isn't working.

[Strum355]

Looks like backward-cpp got removed when this repo got shuffled around into being a "fork". Heres the old PR from when it was introduced #32.

Of note, it didn't seem to work in all situations for reasons beyond my capability to explore, specifically I believe if it segfaulted in one of the worker threads it would not work