Load metadata in stages to accelerate start of simple jobs
Improves metadata loading speed for typical jobs which do not require complete metadata information about the input file. Related to https://its.cern.ch/jira/browse/ATEAM-707 but this is only part of the solution. Another part will come from a better slection of metadata in the "lite" access mode. Tagging @mrenda @tsulaia
Edited by Tomasz Bold