Replace ConfigFactory used in block config with backend for text config so both are consistent.
To ensure that the block and text configuration are consistent, the TextConfig class was refactored into a ConfigFacotry and and TextConfig classes. The ConfigFactory class replaces the previous ConfigFactory used in the block config so that the functions/classes for each block are the same for both and the way that they are configured are the same.
The block config implemented in FullCPAlgorithmsTest.py was updated to use the new back-end.
Many of the functions previously used in TextConfig class were moved to the ConfigSequence class to make interacting with the blocks and block options easier.
The PileupReweighting block for the text config was replaced with the code used for the block config.
The blocks stored in the TextConfig class are now encapsulated in a class that can create an instance of the class/function associated with the block.
Addresses the following: