Expose relevant gateway metrics #21
Description
We want to better understand how we use the RPC gateway, so we will start by adding a minimal set of metrics.
Implementation details
Required metrics:
- number of fulfilled requests per RPC provider
- uptime per RPC provider (health metric)
- number of requests per service (access token) per chain
- total number of requests per chain
Testing details
- manually validate that metrics are available on the local start