[m-rev.] for review: simplify some code in error_util.m

[Zoltan Somogyi]

On Wed, 12 Oct 2022 14:26:37 +1100 (AEDT), Julien Fischer <jfischer at opturion.com> wrote:
> > Any objections, or ideas for better module names?
> 
> No objections from me.
> 
> The diff looks fine.

Thank you.

I just thought of something else. Splitting error_util.m
will require touching many modules, so I thought
I would rename the format_component type to
format_piece, because we already use Pieces
as the standard variable name to refer to lists of
format_components. This would require touching
the same modules, so it makes sense to do both
at the same time. Any objections?

Zoltan.