add some more monitoring plots needed for data taking for Run 3

This adds some plots of the pixel and sct mulgtiplicities as a function of lumi block. It also fixes a bug whereby the monitor histogram rebin functionality was not working.

NB: This package contains only standalone executables that do not run within athena, so only the build tests are relevant - if any of the "required" tests fail, it can not be due to this package, since the CI tests do not run any of these executables.