Ruler: implement recording rule metrics backfilling

[dannykopping]

Is your feature request related to a problem? Please describe. Recording rules produce metrics based on a given query, but only from the point in time when the recording rule was created.

Describe the solution you'd like I'd like the ability to backfill metrics from logs. Prometheus have implemented backfilling and we can use the same mechanism, provided we produce a valid OpenMetrics file.

Describe alternatives you've considered N/A

Additional context Add any other context or screenshots about the feature request here.