TrigCost: Add cost metadata file
Save cost processing metadata into ntuple, then, during post processing, into metadata.json file:
- monitors that were on
- additional hash map path
- eb weighting flag
- base event weight value
- run number
- Atlas Project, Version
- HLT menu (will not be displayed on website - tmi, needed for chain->alg mapping)
possible extensions: smk, l1psk key, hltpsk key, user details (passed by flag), rob2ros map path, processing command
example: https://atlas-trig-cost.cern.ch/?dir=aporeba&type=&tag=data18-13TeV&run=00000009&page=metadata