Session start event

[alexanderkirtzel]

Is your feature request related to a problem? Please describe.
I want client-side handling of the session state. It's nice to know about possible campaign parameters on a client site.
The walker should be able to fire a session start event under specific circumstances like a page view event.

Describe the solution you'd like
It should support a version without the use of any storage to offer a GDPR-compliant measurement.
Properties should contain parsed campaign, medium, and source information.
It should be possible to enable or disable the auto event.
It should be disabled by default.

Describe alternatives you've considered
Server-side handling but it requires communication with (other) servers.

[alexanderkirtzel]