Changes on KPI Value Writer and Telemetry Backend

- Renamed the method to "KafkaKpiConsumer" to avoid conflict with the "KafkaConsumer" import in KpiApiWriter.
- Removed unnecessary imports in KpiWriterToProm.
- Added `get_service_port_grpc` call and imports in the Telemetry backend service.
- Added new libraries to `requirements.in` for Telemetry.