Reset Session and IDs

[t-unit]

Currently there seems to be no way to reset session information (sessionsCount, firstVisit, ...) as well as the visitor id. I would propose some functionality that enables deleting all stored data in the user defaults for a given MatomoTracker instance that keeps the instance usable and in correct state afterwards.

One use case for this is binding the session information to a user and not to the device. E.g. calling reset after user-logout and not keeping the session count etc.

Happy to supply PR with the proposed feature.

[SW-Vincent]

Hi, just a question about this topic : what is the default behaviour of a session then ?