Refactor prometheus-configs to allow for PromTool unit testing

[ChristianZaccaria]

Issue

We would like to create and perform unit tests on the rules that are added. To achieve this, the simplest way is to make use of PromTool. PromTool requires the alerts to be in their own yaml file as the tool is not able to directly parse from the ConfigMap.

Possible Resolution

• Move alerting-rules and possibly recording-rules from the ConfigMap to their own files.
• Create Make target that makes use of PromTool to automatically run all tests.
• Include a simple unit test to verify this new feature.