Create the argocd resources within the namespaces specified

[cmoulliard]

• Create the argocd resources within the namespace specified within the backstage template as parameter
• Deploy the tekton resources within the application namespace to avoid to have to create namespace-build, namespace-test
• Issue #10

Remark: This change will allow to install backstage (see q-shift/backstage-playground project) within the same namespace as argocd Applications CR