Enable GitLab pages without user custom domains

Enables the use of GitLab pages without configuring user custom domains. Also added the ability to configure the port of pages in the virtual service, as sets it to port 80, whereas the pages pod uses port 8090. Both default to the same behavior as before if not specified in values, though I'm not sure how that worked with the port being 80. Fixes #196 (closed)

chart/templates/bigbang/pages-virtualservice.yaml

@@ -30,7 +30,15 @@ spec:
     - name: "pages"
       route:
       - destination:
+          {{- if .Values.istio.pages.customDomains.enabled }}
           host: {{ .Release.Name }}-gitlab-pages-custom-domains.{{ .Release.Namespace }}.svc.cluster.local
+          {{- else }}
+          host: {{ .Release.Name }}-gitlab-pages.{{ .Release.Namespace }}.svc.cluster.local
+          {{- end }}
           port:
+            {{- if .Values.istio.pages.port }}
+            number: {{ .Values.istio.pages.port }}
+            {{- else }}
             number: 80
+            {{- end }}
 {{- end }}