RFileLoggerBody - class to provide all internal data for the client side

This class contains all data members which would otherwise be in the RFileLogger class. They are instead in this file since that keeps the size of RFileLogger to a minimum, and also means its size will not change very often. By keeping the RFileLogger class size to a minimum, it means in release builds where no logging is to be included, only a skeleton of the RFileLogger is built into each component, numbering a handful of bytes.