Revise eval_bootstrap functions to create one user facing function

[HeikoSchuett]

Is your feature request related to a problem? Please describe.
In the inference module there are several different functions for bootstrap based evaluation, which implement overlapping code and sometimes allow the user to even do the same thing. I think this is confusing and could lead to maintenance issues and users being confused which function they should run.

Describe the solution you'd like
I believe eval_bootstrap, eval_bootstrap_rdm, eval_bootstrap_pattern, bootstrap_crossval, eval_dual_bootstrap could be consolidated into a single user facing function.

Describe alternatives you've considered
We could keep it of course, but I think it would be good to reduce it at least somewhat.

Volunteer
I will probably do this myself, just putting the rationale here.