Implement all PosteriorDB models using `DynamicPPL.@model`.

[yebai]

Let's add all PosteriorDB models to https://github.com/JuliaBayes/posteriordb-bench/

See,

• https://github.com/JuliaBayes/posteriordb-bench/
• https://github.com/JasonPekos/TuringPosteriorDB.jl
• https://github.com/stan-dev/posteriordb