Clean up reader and associated classes

Context

The Reader classes contained old methods and attributes that are no longer used in the new system. Some attributes needed to be accessed differently.

Summary

The code that was changed was mainly code that was not used anywhere in the system. Two changes to functionality are regarding the ReaderFactory and the "trigger time".

• The ReaderFactory now returns a Reader instead of a ReaderIterator. The RunManager can use the reader to update the values for numBinsBaseline, ampMax and ampMin if they have been modified when a Reader was created. To check if they have been modified, use the method yLimitsKnown() from Reader.
• Each channel now stores the "trigger time" for the Event. Anywhere in the old system that used getTriggerTime() from the Reader can now access this through the Channel instead.

How was this tested?

The compiled code runs as it did before.