Use the "uniformly samples" warning in the `extract_features` method to issue a warning there as well as some features assume uniformly sampled time series as well

[nils-braun]

we could use use that warning in the extract_features method to issue a warning there as well as some features assume uniformly sampled time series as well.

If we do that, we could move lines 538-549 into its own method raise_warning_on_non_uniform_index or so

_Originally posted by @MaxBenChrist in https://github.com/render_node/MDE3OlB1bGxSZXF1ZXN0UmV2aWV3NDAwNTQ3ODMx/pull_request_reviews/more_threads