feat(ingress): add TLS configuration for staging hosts

Add TLS configuration for staging-shiny and staging-shiny-api 
hosts in the ingress resources. Create a new namespace for 
ingress-nginx to better organize resources. Update kustomization 
files to include new certificates and secrets. Streamline setup 
process with improved wait commands for pod readiness.

k8s/infra/kustomization.yaml

@@ -0,0 +1,22 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+resources:
+- postgres.yaml
+- rabbitmq.yaml
+- namespaces.yaml
+helmCharts:
+- name: external-secrets
+  namespace: external-secrets
+  includeCRDs: true
+  releaseName: external-secrets
+  repo: https://charts.external-secrets.io
+  version: 1.1.1
+- name: cert-manager
+  namespace: cert-manager
+  includeCRDs: true
+  releaseName: cert-manager
+  repo: https://charts.jetstack.io
+  version: v1.19.2
+  valuesInline:
+    crds:
+      enabled: true