`arvados_*` modules should have option to set the full state

[colin-nolan]

e.g. if keep nodes are deleted, the API server won't be notified:

hgi-systems/ansible/roles/arvados-cluster/tasks/main.yml

Lines 23 to 41 in 1515d8b

	- name: create keep_service entries for keep hosts
	delegate_to: "{{ arvados_cluster_delegate }}"
	arvados_keep_service:
	api_host: "{{ arvados_cluster_api_host }}"
	api_token: "{{ arvados_cluster_superuser_api_token }}"
	service_host: "{{ item }}"
	service_type: blob
	with_items: "{{ arvados_cluster_keep_hosts }}"
	- name: create keep_service entries for keep proxies
	delegate_to: "{{ arvados_cluster_delegate }}"
	arvados_keep_service:
	api_host: "{{ arvados_cluster_api_host }}"
	api_token: "{{ arvados_cluster_superuser_api_token }}"
	service_host: "{{ item }}"
	service_port: 443
	service_ssl_flag: True
	service_type: proxy
	with_items: "{{ arvados_cluster_keepproxy_hosts }}"