ATR-28888 -- Reimplement End-of-Event processing in HLT

We operate LAr noise burst detection and MET trigger reconstruction for monitoring in events accepted by the HLT. This sequence was lost in the CA menu generation refactoring, so reintroducing it here.

It fits more naturally in GenerateMenuMT.py than where it was previously in HLTCFConfig.py. Arguably even more apt here in TriggerConfig.py c.f. an old TODO note, but that option would require us to separately extract the chainDicts.

Sequence doesn't seem to be added correctly to HLTFinalizeSeq currently, needs more debugging.