[demo] Support Prometheus v3 translation_strategy NoUTF8EscapingWithSuffixes

[Pionerd]

When following https://prometheus.io/docs/guides/opentelemetry/, setting the translation_strategy to NoUTF8EscapingWithSuffixes renames the metrics ingested into Prometheus, e.g. from traces_span_metrics_duration_milliseconds_bucket to traces.span.metrics.duration_milliseconds_bucket.

I do not immediately oversee all consequences of this, one is that the Grafana dashboards break.

Is this translation_strategy something we like to implement? I can start on a PR if so. The reason is that we would like to set this strategy in an existing Prometheus instance we fully integrated with the demo app.