Add protection against using too many input LHE files

Changes introduced

Throw error when total LHE events uses as input is much (factor of 2) higher than the number of events that the job requests in order to ensure we don't waste LHE input.

In the example below a user used:

• evgenConfig.nEventsPerJob=2000
• evgenConfig.inputFilesPerJob = 15
• the LHE files had 20k events each => 300k in total
• the efficiency was 11% so one would expect 33k events in the EVNT while the job asked for 2k only

Tests

Issues resolved

Closes #