Make static into member data of PixelFitterByHelixProjections

Valgind found this statics being modified from multiple threads.
Moving them to be member data solves several problems including the
thread safety issues. The other problem was if multiple
PixelFitterByHelixProjections were being used in a job and the job
crossed an IOV boundary, only one of them would get updated EventSetup
data.
Merge pull request #3513 from Dr15Jones/threadSafePixelFitterByHelixProjections

Multithreading -- Make static into member data of PixelFitterByHelixProjections