Implementation of log-based alerting

[Rotfuks]

Motivation

Based on our initial investigation in roadmap#3178, introducing Multi tenancy roadmap#3448 and storing logs in the right tenants will also allow us to create alerts within those tenants based on logs. This allows customers to not just include metrics but also log information in their alerting rules.

Todo

• Implement log-based alerting for logs
  • It should be able to create alerts for logs on the MC and the WCs
  • Customers should be able to define alerting rules the same way they do it for metrics
  • We need to clarify if we want to/need to handle log-based compared to metric-based alerting rules (different folder structure in prometheus-rules?)

Outcome

• Customers are able to create log-based alerts.