**Changes by micmaestrini:**
Online ADS during propagation has been added leveraging base submodules _integrator and _ADS.
In particular the following changes have been implemented:
1. Added four new methods for the class ADS: compute the size and center of a given domain, determine if a point lies inside a domain, replay a history of splitting along given directions.
2. Added the new submodule _ADSintegrator which implements a subclass of _integrator that deals with splitting during the propagation with variable stepsize.
3. Fixed type hinting for time variables in the integrator (only available for float, therer is a tutorial that explains how to deal with DA time).
4. Fixed a couple bugs in integrator: deal with integer input time, avoid crash while adapting the final stepsize to avoid an inf (even though it was not used).
5. Removed annoying prints from ADS tutorials.
6. Created a tutorial for online ADS.
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Additionally, fix issue 6.