`update_parameter_proposal()` needs to be generalized

[tbrown122387]

update_parameter_proposal() (in all four LW filter classes) needs to be generalized to use the unnormalized weights. Right now, it assumes all weights are uniform, which only occurs if resampling has just been performed at the end of the previous iteration.

[tbrown122387]

Also somewhere in the documentation it should mention tjay the original paper doesn’t prescribe resampling but the APF provides for the possibility