Add RLN Proof Generation Time Panels

[mamoutou-diarra]

Context

This PR adds new grafana panels for RLN Proof Generation time. There's no metrics for Generation time, it is computed from log lines then transformed into timeseries.

Main changes

• Added Grafana panels for RLN Genaration time: compute the time difference between RLN proof (start) and RLN proof generated successfully (end) from log, then apply grafana transformations to convert into timeseries
• Increased victorialogs vlselect timeout from 30s to 120s to allow querying large log data
• Increased vlselect Memory Limit to 32Gi to allow computation on large log data

Caveats

• The current RLN Generation time is not true, it is should use Generating RLN proof as start, but this line is visible only log level is TRACE, but when I set level to TRACE, metrics are not available. I'll report the issue to Akshaya and prem (maybe it's a design choice).