Dropped unused code around HitExpectation
Part of the set of MRs LHCb!3369 (merged), Lbcom!594 (merged), Rec!2670 (merged), !1034 (closed), Boole!375 (merged)
Part of the set of MRs LHCb!3369 (merged), Lbcom!594 (merged), Rec!2670 (merged), !1034 (closed), Boole!375 (merged)