FTRawBankDecoder to deal with large clusters
FTClusters can have maximum size 4. This creates many fragmented clusters. We would like to save only the first and last fragments. New decoder will make the middle clusters. Additionally we now combine two fragments to make clusters up to size 8.
The decoder will process old files digitized with Encoder version 2 same as before except isLarge = 0 => pseudoSize = 4 for unfragmented clusters (real size is 1..4) isLarge = 1 => pseudoSize = 0 for fragmented clusters (large clusters fragmented to size 4 or less.)
Newly digitized files (Encoder version 3) will be further processed: pseudoSize = 4 for unfragmented clusters (real size is 1..4) pseudoSize = 5..8 for merged fragmented clusters (this is their real size) pseudoSize = 0 for fragmented clusters (we keep these to avoid hit inefficiency but they need to be treated differently in tracking, preferably removed from track fitters)
Rec!838 (merged) is using pseudoSize to assign uncertainty of the hits for the track fits. These can cause efficiency drop in old digi files since clusters of size 5..8 are treated same as other fragmented clusters. However for new digi files, timing will improve as number of split clusters would be less and efficiency can be improved with better parametrization of uncertainty.
Resolves: LHCBSCIFI-93, LHCBSCIFI-100