Performance: Potential optimisation if avoid always creating error context

Context

See short "Explanation" section of CXXCBC-388 for background context, test app, and terms used below.

Issue

If I'm reading the code correctly, it looks like make_key_value_error_context is always called, irrespective of whether the command succeeds or fails?  If not and it's only closed on error, then no action needed, please close the ticket.

But if it is, then the profiler indicates it's a non-trivial (3.66%) amount of the total time when doing bulk operations, is spent here: