feat(core): Add Prometheus metrics for n8n events and api invocations (experimental) (#5177)

* create prometheus metrics from events

* feat(core): Add more Prometheus metrics (experimental) (#5187)

* refactor(core): Add Prometheus labels to relevant metrics

* feat(core): Add more Prometheus metrics (experimental)

* add 'v' prefix to value of version label

Co-authored-by: Cornelius Suermann <cornelius@n8n.io>

packages/cli/package.json

@@ -136,6 +136,7 @@
     "dotenv": "^8.0.0",
     "express": "^4.16.4",
     "express-openapi-validator": "^4.13.6",
+    "express-prom-bundle": "^6.6.0",
     "fast-glob": "^3.2.5",
     "flatted": "^3.2.4",
     "google-timezones-json": "^1.0.2",