REFACTOR(vault): move resources to manifests

- Move additional resources to manifests/ folder
- Separate from Helm chart configuration

vault/manifests/cluster-secret-store.yaml

@@ -0,0 +1,17 @@
+apiVersion: external-secrets.io/v1
+kind: ClusterSecretStore
+metadata:
+  name: vault-backend
+spec:
+  provider:
+    vault:
+      server: http://vault.vault.svc.cluster.local:8200
+      path: secret
+      version: v2
+      auth:
+        kubernetes:
+          mountPath: kubernetes
+          role: external-secrets
+          serviceAccountRef:
+            name: external-secrets
+            namespace: external-secrets