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_node.py

@@ -76,19 +76,11 @@ options:
         required: false
         type: str
 extends_documentation_fragment:
-    - docker
+  - docker
+  - docker.docker_py_1_documentation
 requirements:
-    - "python >= 2.6"
-    - "docker-py >= 1.10.0"
-    - "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-       module has been superseded by L(docker,https://pypi.org/project/docker/)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).
-       For Python 2.6, C(docker-py) must be used. Otherwise, it is recommended to
-       install the C(docker) Python module. Note that both modules should I(not)
-       be installed at the same time. Also note that when both modules are installed
-       and one of them is uninstalled, the other might no longer function and a
-       reinstall of it is required."
-    - Docker API >= 1.25
+  - "docker-py >= 1.10.0"
+  - Docker API >= 1.25
 author:
   - Piotr Wojciechowski (@WojciechowskiPiotr)
   - Thierry Bouvet (@tbouvet)
@@ -143,16 +135,16 @@ node_facts:
 try:
     from docker.errors import APIError
 except ImportError:
-    # missing docker-py handled in ansible.module_utils.docker_common
+    # missing docker-py handled in ansible.module_utils.docker.common
     pass
 
-from ansible.module_utils.docker_common import (
+from ansible.module_utils.docker.common import (
     DockerBaseClass,
 )
 
 from ansible.module_utils._text import to_native
 
-from ansible.module_utils.docker_swarm import AnsibleDockerSwarmClient
+from ansible.module_utils.docker.swarm import AnsibleDockerSwarmClient
 
 
 class TaskParameters(DockerBaseClass):