faster version of LArCelldeadOTXTool

Faster version of LArCelldeadOTXTool: Calculate and cache as much as possible on the first event (using std::call_once), so we have less work to do in the event loop. This implicitly assumes that the list of bad/missing FEBs does not change in the course of the event processing. This limitation could be overcome by splitting off the code executed by call_once on the first event into a conditions algorithm.

I tested the code by running it on data where the FEB was still present, eg I have reference cell energies to compare against. In order to obtain a acceptable correlation, an energy cut on the super-cell energy was introduced. Also: Ignore bad super-cells.

cc @pavol @ekay