[Mono.Debugging.Soft] Catch and log exceptions thrown inside of OnConnectionError
[Mono.Debugging.Soft] Catch and log exceptions thrown inside of OnConnectionError

Fixes https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1074174/

Unity-Technologies/debugger-libs,Unity-Technologies/debugger-libs,mono/debugger-libs,mono/debugger-libs