Make the analysis of experiments more flexible

• Allow arbitrary prometheus range queres (update prometheusResponse)
• Allow usage of more than one slo checker
• Update the json which send to the python slo checker
• refactoring
• Update CRDs in order to set the query string as an dedicated parameter for a slo checker
• Update exisiting python slo checker in order to use the new JSON format (handled in !185 (merged))

Closes #249 (closed)

theodolite/src/test/resources/k8s-resource-files/test-execution-update.yaml

@@ -15,7 +15,6 @@ spec:
     - sloType: "lag trend"
       prometheusUrl: "http://prometheus-operated:9090"
       offset: 0
-      query: "sum by(group)(kafka_consumergroup_group_lag >= 0)"
       properties:
         threshold: 2000
         externalSloUrl: "http://localhost:80/evaluate-slope"