Return kwargs when running `generate_all_posterior_samples` method in `SamplesDict`
The purpose of this MR is to allow for user to add 'return_kwargs=True' when using the 'generate_all_posterior_samples' method in SamplesDict.
The purpose of this MR is to allow for user to add 'return_kwargs=True' when using the 'generate_all_posterior_samples' method in SamplesDict.