MTCalibPebConfig: Fix sequences and menu configuration

Fix two issues in MTCalibPebConfig.py:

1. Ensure trigger summary algorithms run after hypothesis algorithms by arranging them in sequentially-ordered sequences similarly as it is done in the standard Trigger configuration (see TriggerJobOpts/TriggerConfig.py). Fixes ATR-22987.
2. Ensure HLTConfigSvc configured implicitly by the L1Decoder setup has the same value of the property JsonFileName as the one configured explicitly later. Otherwise there is a conflict (configuration error). Also add extra entries in the dummy menu file which are required by L1Decoder. Fixes ATR-23059.