Modify TTree Structure

Context

Modify the TTree Structure to have eventID and triggerTime at the event level.

Summary

eventID and triggerTime are now both at the same level as the Channel branches. They can still be used for filtering, but they are not written multiple times for each Channel.

This is the new structure of the TTree:

I also removed some repeating code from TTreeWriter that was unnecessary.

How was this tested?

I tested it with single channel and multi channel data and the result appears to be the same as before, except for the different structure.