explore timing and sample efficiency with barker proposal 

https://blackjax-devs.github.io/blackjax/autoapi/blackjax/mcmc/barker/index.html

## Resources
- https://github.com/gzanella/barker/blob/master/functions.R
- https://num.pyro.ai/en/stable/_modules/numpyro/infer/barker.html
- https://arxiv.org/pdf/1908.11812
- https://academic.oup.com/biomet/article/110/3/579/6764577