chore: create new RLN Grafana panel that counts the number of attached proofs per light client

[Ivansete-status]

Description

The following has been implemented in js-waku. We need to have an appropriate Grafana panel where we can see the number of proofs generated per light-client within a RLN epoch (10 min at this time.)

Ideally, the panel should show:

• number of proofs generated per light-client
• Representation of the proof budget a full node has per epoch. For example, TWN nodes are configured with a max limit 100 messages per 10 minutes. Then, we need to show the proofs that are left each time to reach the max limit.

For more context, the current limit for TWN is configured in:

nwaku/waku/factory/networks_config.nim

Lines 29 to 30 in 01fe4d1

	rlnEpochSizeSec: 600,
	rlnRelayUserMessageLimit: 100,

Related issue

[Epic: js-waku] RLN in resource-restricted environments - waku-org/pm#169
https://docs.google.com/document/d/1L8HvXtAYk-JqQL6w3RgCskXwegcTa0J5nyH9YL4LrQE/edit#heading=h.vqpbd9ne1q33

[fryorcraken]

In grafana you can set and display thresholds. Would be useful for this graph