Cardano-node: [1.24.1] - Some Prometheus metrics were changed

[dorin100]

Internal/External
Internal if an IOHK staff member.

Summary
cardano.node.Forge.metrics and cardano.node.ChainDB.metrics are not working.

EX: blocks is now cardano_node_metrics_blockNum_int

Expected behavior
All the existing metrics should continue to work OR at least provide clear and meaningful communication/documentation about what is changed.

Additional context

• this might be related to https://github.com/input-output-hk/cardano-node/pull/2158

This has the potential to break the monitoring systems used by SPOs.

[gitmachtl]

I would prefer to have a clean naming scheme, having it all in cardano_node_metrics_xxx

[dcoutts]

We cannot both not change things and also make everything clean and consistent.

At some point to make the naming scheme sane we need to break and change things. We should do that, but not at the same time as people need to upgrade for a hard fork.

[disassembler]

I concur with @dcoutts. We should not break the metrics path for the hard fork and plan on making this change in a future release with a weeks warning at least to the community members that write tools that depend on these metrics.