Implement `PrintReport` for Prometheus Telemetry Sink

[arpitbbhayani]

We need to implement PrintReport for Prometheus Telemetry Sink is not implemented yet. The output format should be exactly the same as the Mem Telemetry Sink. You will need to write prom queries to get the data that we want to report and implement the function.

$ ./membench benchmark --database dicedb \
    --host localhost \
    --port 7379 \
    --num-requests 100000 \
    --num-clients 4 \
    --telemetry-sink prometheus

References

• prometheus.go
• mem.go

Follow the README to see the steps to run the membench with telemetry-sink as prometheus.

ps: Do not wait for anyone to assign the issue, work on it, and submit the patch.

[aasifkhan7]

@arpitbbhayani please review #2