docker modules: various adjustments (#51700)

* Move docker_ module_utils into subpackage.

* Remove docker_ prefix from module_utils.docker modules.

* Adding jurisdiction for module_utils/docker to $team_docker.

* Making docker* unit tests community supported.

* Linting.

* Python < 2.6 is not supported.

* Refactoring docker-py version comments. Moving them to doc fragments. Cleaning up some indentations.

lib/ansible/modules/cloud/docker/docker_swarm_service.py

@@ -335,14 +335,11 @@ options:
     - Before Ansible 2.8, the default value for this option was C(root).
       The default has been removed so that the user defined in the image is used if no user is specified here.
 extends_documentation_fragment:
-- docker
+  - docker
+  - docker.docker_py_2_documentation
 requirements:
-- "docker-py >= 2.0"
-- "Please note that the L(docker-py,https://pypi.org/project/docker-py/) Python
-   module has been superseded by L(docker,https://pypi.org/project/docker/)
-   (see L(here,https://github.com/docker/docker-py/issues/1310) for details).
-   Version 2.1.0 or newer is only available with the C(docker) module."
-- "Docker API >= 1.24"
+  - "docker >= 2.0"
+  - "Docker API >= 1.24"
 notes:
   - "Images will only resolve to the latest digest when using Docker API >= 1.30 and docker-py >= 3.2.0.
      When using older versions use C(force_update: true) to trigger the swarm to resolve a new image."
@@ -529,7 +526,7 @@ EXAMPLES = '''
 import time
 import shlex
 import operator
-from ansible.module_utils.docker_common import (
+from ansible.module_utils.docker.common import (
     AnsibleDockerClient,
     DifferenceTracker,
     DockerBaseClass,
@@ -544,7 +541,7 @@ try:
     from docker.utils import parse_repository_tag
     from docker.errors import APIError, DockerException
 except Exception:
-    # missing docker-py handled in ansible.module_utils.docker
+    # missing docker-py handled in ansible.module_utils.docker.common
     pass