Add tests prometheusrules alerts for relations/spicedb in kessel-stage and equivalent tests in kessel-prod

See,

1. https://service.pages.redhat.com/dev-guidelines/docs/appsre/onboarding/observability/#prometheus-alerts-tests
2. https://gitlab.cee.redhat.com/service/app-interface/-/tree/master/resources/insights-stage/kessel-stage?ref_type=heads 
3. https://gitlab.cee.redhat.com/service/app-interface/-/tree/master/resources/insights-prod/kessel-prod?ref_type=heads 

Definition of done:

1. prometheusrulestests files containing the tests per environment should be committed to app-interface alongside our prometheusrules files.
2. These tests should run on ci jobs and locally without failure.