Save seeds in output?

[veni-vidi-vici-dormivi]

I think I would like to save the seed in the output of mesmer.stats._draw_ar_corr_xr_internal(). Currently we only return the samples but I would like to return a xr.Dataset that has the samples and the used seed to draw them. As a consequence, the seed would be saved in the parameter datasets and can be easily recovered for reproducing the emulations.

[veni-vidi-vici-dormivi]

Or we could just add them manually before saving the emulations which would spare us some renaming...

[mathause]

I think this should get in v1.0.