Use kustomize for install manifest generation

[darkowlzz]

• Adds kustomization files
• kustomize applies the kustomize namespace on all the namespaced resources. Remove the namespace from individual files.
• Move operator optional environment variables to be populated using configmap via config.env file. These variables are read from the execution environment when unset.
• Update makefile to install and use kustomize. scripts/create-manifest.sh is no longer required.

Commands like:

JAEGER_SERVICE_NAME=xyz OPERATOR_IMAGE=repo:tag make install-manifest

continue to work as before.

This change will help with kubebuilder/Operator-SDK v1 project migration.

TODO: update OLM deployment to use configmap for env vars.

NOTE: This should be merged after v2.2 release.