Adding information about bad modules in mkFit

[cerati]

MkFit does not know which missing hits are due to bad modules since it has no access to the database. This may be needed if we want to have a proper counting of missing hits (and aligned with CMSSW).

Two options to implement it are:

1. add hits with large uncertainties (flagged as dead module placeholder). The disadvantage is that we need to make sure the windows are not too small so that we do not pick them up
2. have a space map (possibly the same as the hit partitioning) that indicates if the module covering that area was active. The disadvantage is that it will be one more data structure.