Use tfp.distributions to define priors

[Joshuaalbert]

Is your feature request related to a problem? Please describe. I want all distributions in tf_probability to be available priors in jaxns.

Describe the solution you'd like The user should be able to use any prior in tfp.distributions with minimal code.

Describe alternatives you've considered Buiding them all by hand works so far and allows nitpicking for performance.

Additional context Would be good to merge this with the new substrates additions given that we're going to use tfp for that.