Step 1 to migrate AthenaEventLoopMgr to xAOD
Partial migration of AthenaEventLoopMgr to xAOD::EventInfo. Left to be done:
- Get rid of code around line 640 to read TAG files (we decided to drop this functionality)
- Create xAOD::EventInfo for jobs w/o input (around line 690)
Details are discussed at ATEAM-506. The main goal of this MR is to unblock physics validation (discussed at ATLPHYSVAL-606)
Unfortunately the PhysVal jobs still fail because of another problem.