Code improvement in Localization dir

Hello,

I am new to this repo and was going through the documentation & code. I wanted to brainstorm a bit here.

I was wondering if there's any appetite for improving some of the software design within the Localization directory by introducing a base `BayesFilter` class and extending it for the respective versions, like `EKF`, `ParticleFilter`, etc. This could conceivably make the code across the different filter implementations similar and make adding new filters easier as well by introducing a common filter API for all future filters to implement. Conceivably, this can be wrapped with a few scripts that would depend on the base filter class to provide visualization and testing capabilities.

Thoughts?

Roy.