Feature/features on features

[Scott-Simmons]

PR contains:

• Features on features function extract_feature_dynamics()
• Generate pdf of feature dynamics function to assist with interpretation gen_pdf_for_feature_dynamics()
• Engineer input timeseries function by taking differences within a timeseries (i.e. time differences) and by taking differences between different series (i.e. phase differerences) engineer_input_timeseries()
• Function to get feature time series and feature dynamics dictionaries derive_features_dictionaries()
• Notebook demonstrating the changes in this PR 06 tsfresh on tsfresh.ipynb
• Tests written in the same framework as the rest of tsfresh (@kempa-liehr will be worth having a chat about this)

@andreas the best place to start will be to run tsfresh/feature_extraction/feature_dynamics_example.py and also to read the notebook 06 tsfresh on tsfresh.ipynb

Suggested workflow

1. Make this PR into tsfresh on tsfresh branch (Nil's original branch)
2. @kempa-liehr/@nils-braun to review this PR
3. @Scott-Simmons and @Louis-Jarvis to make suggested changes in this PR and merge into Nil's branch
4. Make PR from Nils branch to Main
5. Merge Nil's branch into main

PDF output