Remove FinalPath

[makortel]

Description

Relevant discussion elsewhere

• place OutputModules on EndPaths (not FinalPaths) in HLT configs hlt-confdb#103
• HLT menu development for 15_0_X (2/N) [15_1_X]  cmssw#47529

FinalPath work consisted from these PRs

• Fix logic error in FinalPath checks cmssw#42936
• Fixed replace with FinalPath cmssw#36937
• fixing removal of modules from FinalPath cmssw#37022
• Added FinalPath implementation cmssw#36398

Was requested to be backported to 15_0_X. Backport is in cms-sw/cmssw#47583

[makortel]

The FinalPath PRs did some reorganization of code, so blindly reverting them would likely not be the best approach.