chore(server): split gcloud sql proxy into a separate deployment (#5101)

After merge this pull request, need to change the `DATABASE_URL` in environment secrets (stable/beta) from `127.0.0.1` to `affine-cloud-sql-proxy`

.github/helm/affine/charts/gcloud-sql-proxy/templates/service.yaml

@@ -0,0 +1,17 @@
+{{- if .Values.global.database.gcloud.enabled -}}
+apiVersion: v1
+kind: Service
+metadata:
+  name: {{ include "gcloud-sql-proxy.fullname" . }}
+  labels:
+    {{- include "gcloud-sql-proxy.labels" . | nindent 4 }}
+spec:
+  type: {{ .Values.service.type }}
+  ports:
+    - port: {{ .Values.global.database.port }}
+      targetPort: cloud-sql-proxy
+      protocol: TCP
+      name: cloud-sql-proxy
+  selector:
+    {{- include "gcloud-sql-proxy.selectorLabels" . | nindent 4 }}
+{{- end }}