Add runBenchmarkWith, general benchmark runner

[phadej]

Refactor runBenchmark to use it. Resolves #254

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I opted out to generating some data-type with configuration etc. The logic is just easier to write as code directly.

[phadej]

I'll add semigroups compat if this is otherwise ok, or when I make tweaks.

[phadej]

I changed the type of function. It fits better the usage where some analysis is done already on each step (in ~bayesian style), so you won't end doing it twice on the last sample (and without access to the state).

[phadej]

I don't need this functionality anymore.