Reduce arguments across functions

[seabbs]

As apart of the next release it might make sense to deal with some of the current argument bloat.

One major contributor to the number of arguments are the stan controls. As stan_args allows any arguments to be passed to stan the number of surfaced arguments could potentially be reduced (i.e removing warmup, chains, adapt delta etc) and reducing these to internal defaults. This would however be a fairly substantial breaking change for any downstream users.