met uncertainty tool (in PAT) fixes for 72X releases

The MET uncertainty tool in PAT has been updated accordingly to the last development changes in 72X releases, and can go to the central release now.

Pat MET names have been also updated in order to match the new naming convention.

Matthieu

@mmarionncern, thank you for the link to an example code. I can see that *phi* would make a bit easier to code there. However, I don't think that it is making much easier. On the other hand, there are many drawbacks with phi in the class.

The memory cost that you mentioned is one of the drawbacks. This struct is an event content of RECO and AOD. So although the cost might be small for one instance of the struct, it might not be so small for all instances stored in RECO and AOD combined.

Another drawback is that we will have to keep phi always consistent with metx and mety. How do we implement the consistency? Which class should be responsible for the consistency? These variables are public, i.e., any class can change the value. Should we review all classes that access to the struct? Should we make them private and write appropriate accessors? That will make us revise all classes that write and read this struct.

Adding the redundant variable will raise many other questions. I don't think this change will make the development easier.