SANS: Quiet Count Measurement Mode

It would be very convenient to have a measurement mode that sets up the dae and vetos for quiet counts before the startup, e.g. just calling a command do_sans(... , dae="quiet"). Currently we set it up either manually or with a script that is stored somewhere.

Start by locating the do_sans entry point and reviewing how dae and vetos are currently configured manually or by script. Done means a quiet-count mode can configure them before startup through the requested command option, with existing behavior preserved.

Written by the indexing model from the issue text.