Resolve the Grafana metrics discrepancies

[stranger80]

• Ensure that "compilations" and "plugin launches" counters are also reflected in the Prod Grafana Dashboard
• Filter out OPTIONS requests from 'metrics detection' code
• Investigate the weird zksync_api_num_plugin_launches counter increase phenomenon for "prod" env:

[stranger80]

It appears that the compile and launch metrics currently in place are "double-counting" (OPTIONS requests being counted separately from GET/POST requests) - this will be adjusted.
It is unclear why historically the counter values have been reset around 30th Sept-1st Oct - this hasn't been triggered by container restarts and it can be demonstrated that plugin upgrades have not impacted the aggregated values on eg. 28th Sept.
As they have been stable in Oct, we'll continue with the rollout of current release and observe the results of that.

[taco-paco]

#219