Refactor asset-manager clamav labels

Description:
- Currently `clamav-pvc` will match onto any `PersistentVolume` with `app.kubernetes.io/instance: asset-manager` as this is contained in `asset-manager.selectorLabels`. However if another `PersistentVolume` were to be deployed with `asset-manager.selectorLabels` there is a chance it will match onto that rather than `clamav-pv` which is the wrong result
- Ensure it only matches on labels that end in `-clamav-db` preventing this mixup
- As part of #1883

charts/asset-manager/templates/clamav-pvc.yaml

@@ -17,4 +17,5 @@ spec:
       storage: {{ .Values.nfs.clamAvStorage }}
   selector:
     matchLabels:
-      {{- include "asset-manager.selectorLabels" . | nindent 6 }}
+      app.kubernetes.io/name: {{ $fullName }}-clamav-db
+      app.kubernetes.io/component: {{ $fullName }}-clamav-db