improvement: Generate aws-auth configmap's roles from Object. No more string concat. (#790)

Do not use string concat to generate a YAML data structure

Co-authored-by: Thierno IB. BARRY <ibrahima.br@gmail.com>

templates/worker-role.tpl

@@ -1,8 +0,0 @@
-- rolearn: ${worker_role_arn}
-  username: system:node:{{EC2PrivateDNSName}}
-  groups:
-    - system:bootstrappers
-    - system:nodes
-    %{~ if platform == "windows" ~}
-    - eks:kube-proxy-windows
-    %{~ endif ~}