benchmark

Add option to get the verbosity provided by commandline flag -v (#1330) (#1397)

* Add option to get the verbosity provided by commandline flag -v (#1330)

* replace assert with test failure

asserts are stripped out in non debug builds, and we run tests in non-debug CI bots.

* clang-format my own tweak

Co-authored-by: Dominic Hamon <dominichamon@users.noreply.github.com>