remove legacy G4 files, introduce standard fcl directory

[cerati]

This PR does 3 things:

1. removal of the legacy G4 fhicl files
2. creating of a "standard" folder pointing to the standard production fhicl files
3. centrally suppress warning messages from SimDriftElectrons, which currently overwhelm log files

Format of fcl files in the standard directory is:
standard_${data/mc}_${workflow}_${step}_icarus.fcl

[SFBayLaser]

I can't go through every file but I did not see any that were deleted that looked like a mistake.
One question: should we remove "refactored" from fcl names since that won't have meaning going forward?

[cerati]

eventually yes, but for now I would not do it to avoid breaking CI tests and current production configs. Once they all switch to the standard fcls it will be easier to rename