When a custom TraceRay filter / EnumerateEntities enumerator callback
throws an exception we currently continue execution and then return
execution to the calling code as if there were no problems. This
currently causes a heap tracking issue in SourcePawn, but even ignoring
that it is likely the wrong behaviour and differs from our other
synchronous callbacks.
This change causes the exception to be caught, immediately terminates
the trace / enumeration, and propagates the exception state back to the
calling plugin correctly. The implementation here is based on how
SortCustom1D handles exceptions.
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