Draft: Trigger: Fix xAOD::AuxSelection WARNING Selected dynamic Aux atribute not found in the registry

A proposal to fix ATR-22421, consists of two changes (separate commits):

1. Initialise Trigger EDM dynamic aux accessors during configuration. A "python" solution based on initialising the accessors with cppyy is used.
2. Stricter checks for unwanted messages. Make check_log.py treat the now-fixed warnings as errors and reduce the warning count thresholds in two tests which check them.