Simplify banditpam implementation

[markymarkdavis]

This is a two part issue that Alex Lazea and I can help implement:

1. Removing any duplicated/unused code from the banditPAM codebase.
   • We're specifically targeting either pieces of code that aren't being used or other code that is creating class attributes or
     other non optimal pieces of code
2. Simplifying the algorithm itself into a couple simpler functions with a rewrite of some of those functions.
   • This is to make the code more optimized by replacing the for loop as an apply function.
   • We will also be looking to combine the build and swap methods of banditPAM into one or two methods that will be simpler to read