Enable delegating all downloads (binaries, images, kubeadm images) (#4420)

* Download to delegate and sync files when download_run_once

* Fail on error after saving container image

* Do not set changed status when downloaded container was up to date

* Only sync containers when they are actually required

Previously, non-required images (pull_required=false as
image existed on target host) were synced to the target
hosts. This failed as the image was not downloaded to
the download_delegate and hence was not available for
syncing.

* Sync containers when only missing on some hosts

* Consider images with multiple repo tags

* Enable kubeadm images pull/syncing with download_delegate

* Use kubeadm images list to pull/sync

'kubeadm config images pull' is replaced by collecting the images
list with 'kubeadm config images list' and using the commonly
used method of pull/syncing the images.

* Ensure containers are downloaded and synced for all hosts

* Fix download/syncing when download_delegate is a kubernetes host

roles/download/tasks/sync_file.yml

@@ -0,0 +1,53 @@
+---
+- name: file_download | create local download destination directory
+  file:
+    path: "{{download.dest|dirname}}"
+    state: directory
+    recurse: yes
+    mode: 0755
+  delegate_to: localhost
+  become: false
+  run_once: true
+  when:
+    - download_delegate != "localhost"
+    - download_run_once
+    - download.enabled
+    - download.file
+
+- name: file_download | copy file to ansible host
+  synchronize:
+    src: "{{ download.dest }}"
+    dest: "{{ download.dest }}"
+    use_ssh_args: "{{ has_bastion | default(false) }}"
+    mode: pull
+  run_once: true
+  become: false
+  when:
+    - download.enabled
+    - download.file
+    - download_run_once
+    - ansible_os_family not in ["CoreOS", "Container Linux by CoreOS"]
+    - inventory_hostname == download_delegate
+    - download_delegate != "localhost"
+
+- name: file_download | upload file to nodes
+  synchronize:
+    src: "{{ download.dest }}"
+    dest: "{{ download.dest }}"
+    use_ssh_args: "{{ has_bastion | default(false) }}"
+    mode: push
+  become: true
+  register: get_task
+  until: get_task is succeeded
+  retries: 4
+  delay: "{{ retry_stagger | random + 3 }}"
+  when:
+    - download.enabled
+    - download.file
+    - download_run_once
+    - (ansible_os_family not in ["CoreOS", "Container Linux by CoreOS"] and
+      inventory_hostname != download_delegate or
+      download_delegate == "localhost")
+  tags:
+    - upload
+    - upgrade