on the `Grafana` add new graph to visualize aggregator value from `AggregatorProxy`

[bayram98]

This is just my proposal.

Currently we only track the off-chain fetched price & on-chain submitted value of data feed.

From the users perspective, users needs to call aggregatorProxy to read the data. I realize that if we had a any problem with proxy we couldn't see it easily from your current monitoring system.

To improve coverage of our monitoring the system, I think we need to add the price table which read the aggregator value from the AggregatorProxy address.