minor updates: plotting functions, exp correction

[n-leo]

• functions to plot the stream files
• exponential correction of dwell time with growth height

[n-leo]

Alternatively, for the expoential correction intead of the proposed code changes, the ipython notebook examples should be updated to use the HeightCorrectionModel class instead of the old function [which I now have done].

The plot function would be good to accept in the code (I do not find it in the current commit); it can be helpful to plot an already saved stream file to check for the layout etc.

[Skoricius]

Thanks @n-leo! Before I review the PR, can you make sure it passes all the automatic tests? It currently fails formatting, so you need to run formatting by doing black f3ast and isort f3ast. That's going to fix formatting inconsistencies and reduce the diff with the current code.

[Skoricius]

Inactive for 3 months. I've added the essentials bits of this in the main code and closing now.