* Make TelemetryService testable
Timer is extracted for better testability of telemetryservice.
Divided TelemetryService to internal part that:
- contains business logic
- does not contain timer
- and therefore testable
and external part that:
- does not contain business logic
- contains timer to send analytics every 10 seconds for all participants.
- does not need tests
* Add Test_AnalyticsSentWhenParticipantLeaves
* Fix test