feat(dir): add basic prometheus metrics (#757)

* feat: add basic prometheus metrics
* feat: add metrics e2e tests

Signed-off-by: Tibor Kircsi <[email protected]>

Author: tkircsi

Taskfile.yml

@@ -768,6 +768,7 @@ tasks:
       # Port-forward dependency services
       - |
         {{ .KUBECTL_BIN }} port-forward service/dir-apiserver 8888:8888 -n {{ .HELM_NAMESPACE }} &
+        {{ .KUBECTL_BIN }} port-forward service/dir-apiserver 9090:9090 -n {{ .HELM_NAMESPACE }} &
 
       # Delay to ensure services are online
       - sleep 10