Various utilities and plotting tools based on matplotlib

TODO:

1. (bring✅ test refactor) plot_multi_par_var
2. (bring test refactor) normal test visualization
3. (bring test refactor) sankey
4. (bring✅ test refactor) time stamped spectrogram
5. (bring test refactor) activity intervals
6. Create examples
   1. plot_multi_par_var
   2. normal test visualization
   3. sankey
   4. time stamped spectrogram
7. (bring test refactor) dask parallelization ntb
8. (bring✅ test refactor) utils