Unification of GSF and non GSF chain configuration

This addresses part of ATR-24210.

Here am unifying Electron/PrecisionElectronRecoSequences_GSF.py into Electron/PrecisionElectronRecoSequences.py.

The "variant" logic I originally introduced when I unified LRT (before GSF) does make sense now, so am just puting in flags to define whether we are activating HI or LRT or GSF.

Work still need to be done to unify PrecisionElectronMenuSequences_GSF.py but I'll do that in a separated MR to make it easier to review.

This is discussed in ATR-24210 and ATR-24211

Pinging @cjmeyer @safarzad and @dbakshig