BSL update pre sample methods

Summary:

added seeds to all methods that generate data and added option to calculate standard deviations for several simulation counts in one call so that log_SL_dev matches select_penalty where this option was available. now both methods simulate max(n_sim) samples in each iteration and use the first n to calculate the likelihood score for each n in n_sim.

also updated select_penalty to use warnings rather than sklearn.utils._testing since warnings has been used elsewhere in the codebase.

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elfi-dev / elfi