Telemetry update: Split event_sender from event_reader

[ZhidongPeng]

• Add enum TelemetryEvent for current TelemetryGenericLogsEvent, help add more telemetry event types.
• Add struct TelemetryEventVMData for common fields shared between all telemetry event types.
• Refactor event_log bit to able start accept other types of telemetry events.
• Move telemetry sender business logic out of event reader module