Capture memory dump on unhandled / fatal exceptions.

[Alan-Jowett]

Description Consider moving this code wer_report.cpp into catch2. Along with Local Dump Collection this will allow for automatically gathering triage dumps when fatal error occur in a test.

Additional context Running catch2 tests under OpenCppCoverage results dumps not being captured via the normal means, such as ProcDump. The only point where dumps can be captured is a via a top-level vectored exception handler. Dumps can be captured easily using the WER APIs. I would prefer to move this code upstream so everyone benefits.