Simplify input of swappable lambda states

[ajfriedman22]

Problem
Particularly for the MT-REXEE implementation, it is quite difficult to input the swappable states when dealing with multiple replicas. This either requires manual entry or an outside script which is prone to user error.

Solution
Simplify the determination of swappable states by inputting the number of terminal lambda states in each replica which can be swapped (for MT-REXEE this means the # of end states) and then inputting which replicas are swapped which is already a yaml option for the default coordinate swapping function (swap_rep_pattern). From this information a function would determine which global states are swappable. We would still allow for manual entry for edge cases.